question

polar

answer

Molecule with partial charges. Mixes with water.

question

nonpolar

answer

No partial charges. Do not mix with water.

question

electronegativity

answer

Attraction of an atom for electrons in a covalent bond.

question

cohesion

answer

Water molecules sticking to each other.

question

adhesion

answer

Water molecules sticking to other surfaces.

question

solute

answer

Something dissolved in a solution.

question

solvent

answer

Dissolving agent of a solution.

question

isomers

answer

Same atoms but different arrangement.

question

structural isomers

answer

Differ in arrangement of atoms.

question

geometric isomer

answer

Differ in arrangement around a double bond.

question

enantiomers

answer

Structures that are like a mirror-image.

question

alpha glucose

answer

Monomer for starch and glycogen.

question

beta glucose

answer

Monomer for cellulose and chitin.

question

cellulose

answer

Carbohydrate component of plant cell walls.

question

starch

answer

Storage polysaccharide of plants.

question

glycogen

answer

Extremely branched polymer of glucose.

question

chitin

answer

Polysaccharide found in arthropod exoskeletons and fungal cell walls.

question

-ose

answer

Suffix of a sugar.

question

tryiacylglycerol

answer

Glycerol and three fatty acids.

question

steroids

answer

Made of four rings of carbon.

question

cholesterol

answer

Steroid common in cell membranes, also in many hormones.

question

peptide bond

answer

Bonds that connect amino acids.

question

Fredrick Sanger

answer

Determined amino acid sequence of proteins.

question

disulphide bridges

answer

Reinforce tertiary structure.

question

primary structure

answer

Chain of amino acids.

question

secondary structure

answer

Either an alpha helix or beta pleated sheet.

question

tertiary structure

answer

Results from interactions between side chains.

question

quaternary structure

answer

Results from two or more polypeptide subunits.

question

-in

answer

Suffix of a protein.

question

purines

answer

Bases with a double-ring structure.

question

pyrimidines

answer

Bases with a single-ring structure.

question

phosphodiester bonds

answer

Bonds between phosphate group and pentose sugar in nucleic acids.

question

synthesis

answer

To put together.

question

digestion

answer

To break apart.

question

dehydration synthesis

answer

Condensation reaction where molecules are connected by loss of a water molecule.

question

hydrolysis

answer

Reaction where water split into two hydrogens and one oxygen; this breaks a polymer.

question

anabolism

answer

Metabolic pathways that construct molecules, requiring energy.

question

catabolism

answer

Metabolic pathways that break down molecules, releasing energy.

question

natural selection

answer

A population can change over time if individuals with more fit traits leave more offspring than less fit individuals.

question

evolutionary adaptation

answer

An accumulation of inherited characteristics that enhance organisms' ability to survive and reproduce in specific environments.

question

artificial selection

answer

Humans modifying species for desired traits through selective breeding.

question

decent with modification

answer

Darwin's way of referring to evolution.

question

MRSA

answer

Methicillin-resistant Staphylococcus aureus.

question

fitness

answer

Individuals whose inherited traits confer an advantage have a better chance of surviving in a given environment and will leave more offspring.

question

homology

answer

Similarity resulting from common ancestry.

question

homologous structures

answer

Same structure, different function. Comes from common ancestor.

question

comparative embryology

answer

Embryos of vertebrates share many anatomical homologies.

question

vestigial structures

answer

Are little or no importance to organism, but remain from an ancestor.

question

biogeography

answer

Geographic distribution of species.

question

microevolution

answer

Change in genetic makeup of a population from generation to generation.

question

macroevolution

answer

Evolutionary change above the species level.

question

population

answer

Group of individuals of the same species living in the same area.

question

population genetics

answer

Study of allele frequency distribution and change under the influence of evolutionary processes.

question

gene pool

answer

All the genes in a given population at a given time.

question

allele frequency

answer

Proportion of an allele in a gene pool.

question

Hardy-Weinberg Theorem

answer

Helps measure changes in allele frequencies over time. Provides an "ideal" population to use as a basis of comparison.

question

mutation

answer

Changes in the nucleotide sequence in DNA.

question

sexual recombination

answer

Crossing over and shuffling of genes during meiosis.

question

genetic drift

answer

Change in allele frequencies due to chance.

question

bottleneck effect

answer

When a population has been dramatically reduced, and the gene pool is no longer reflective of the original population's.

question

founder effect

answer

When a small number of individuals colonize a new area; the new gene pool is not reflective of original population.

question

gene flow

answer

When a population gains or loses alleles., movement of alleles into or out of a population due to the migration of individuals to or from the population.

question

genetic variation

answer

Heritable variations in a population.

question

discrete characteristics

answer

Characteristics that are classified on an either-or basis, determined by a single gene locus.

question

quantitative characteristics

answer

Characteristics that vary along a continuum, usually due to influence of two or more genes.

question

geographic variation

answer

Difference in variation between population subgroups in different areas.

question

cline

answer

A graded change in a trait along a geographic axis.

question

relative fitness

answer

Fitness of a particular genotype.

question

directional selection

answer

Shift toward a favorable variation.

question

disruptive selection

answer

Shift toward the extremes.

question

stabilizing selection

answer

Shift that favors the mean.

question

heterozygous advantage

answer

Maintains recessive alleles in a population,

question

sexual selection

answer

Natural selection for mating success.

question

sexual dimorphism

answer

Differences between the sexes in secondary sexual characteristics.

question

speciation

answer

Origin of new species and the source of biological diversity.

question

biological species concept

answer

Species is a group of populations whose members have the potential to produce fertile offspring.

question

reproductive isolation

answer

Barriers that impede members of two different species fro producing fertile offspring.

question

prezygotic barriers

answer

Barriers that impede mating or hinder fertilization.

question

habitat isolation

answer

When two species encounter each other only rarely.

question

temporal isolation

answer

When two species breed at different times of day, season, or years.

question

behavioral isolation

answer

Incompatible courtship rituals, pheromones, or bird songs.

question

mechanical isolation

answer

Morphological differences prevent fertilization.

question

gametic isolation

answer

When sperm can't fertilize the eggs.

question

postzygotic barriers

answer

Barriers that prevent the hybrid zygote from becoming a fertile adult.

question

reduced hybrid viability

answer

When the genes of different species interact and impair hybrid development.

question

reduced hybrid fertility

answer

Sterile hybrids due to uneven chromosome number.

question

hybrid breakdown

answer

Hybrid is fertile, but when they breed the next generation is sterile.

question

allopatric speciation

answer

When a population is divided; leads to speciation.

question

sympatric speciation

answer

Speciation without a divided population.

question

polyploidy

answer

In plants, the result of an extra set of chromosomes during cell division.

question

autopolyploid

answer

Having more than two sets of chromosomes from a single species.

question

allopolyploid

answer

Sterile hybrid is changed to a fertile polyploid due to mutation; fertile with each other, but not parent species.

question

adaptive radiation

answer

Evolution of many new species from a common ancestor as a result of introduction to new environments.

question

punctuated equilibrium

answer

A model of evolution in which a new species will change the most as it buds from a parent species, and then will change little for the rest of its existence.

question

gradualism

answer

A model of evolution in which gradual change over a long period of time leads to biological diversity.

question

heterochrony

answer

Change in the rate or timing of a developmental event; an organism's shape depends on relative growth rate of body parts.

question

allometric growth

answer

Proportioning that gives a body a specific form.

question

homeotic genes

answer

Genes that determine basic features of where a body part is.

question

Hox genes

answer

Class of homeotic genes. Changes in these genes can have a profound impact on morphology.

question

phylogeny

answer

Evolutionary history of a species or group of species.

question

systematics

answer

Analytical approach to understanding the diversity and relationships of present and past organisms.

question

analogy

answer

Anatomical similarity due to convergent evolution.

question

homoplasies

answer

Analogous structures that have evolved independently.

question

taxonomy

answer

A classification of organisms into groups based on similarities.

question

bionomial nomenclature

answer

Scientific name.

question

genus

answer

First part of scientific name.

question

specific epithet

answer

Second part of scientific name.

question

phylogenetic trees

answer

Branching diagrams that depict hypotheses about evolutionary relationships.

question

cladogram

answer

Diagram that shows patterns of shared characteristics.

question

clade

answer

A taxonomic grouping that includes only a single ancestor and all of its descendants.

question

cladistics

answer

A phylogenetic classification system that uses shared derived characters and ancestry as the sole criterion for grouping taxa.

question

monophyletic group

answer

A taxonomic grouping that includes an ancestral species and all of its descendants.

question

paraphyletic group

answer

A monophyletic group in which some descendants of the common ancestor have been removed.

question

polyphyletic group

answer

A taxonomic grouping consisting of several species that lack a common ancestor (more work is needed to uncover species that tie them together into a monophyletic clade).

question

shared primitive character

answer

Trait shared beyond the taxon.

question

shared derived character

answer

Evolutionary novelty unique to that clade.

question

outgroups

answer

Species or group of species closely related to the ingroup.

question

phylograms

answer

Diagram in which the length of a branch reflects number of changes in a DNA sequence.

question

ultrametric trees

answer

Diagram in which length of a branch reflects amounts of actual time.

question

maximum parsimony

answer

"Occam's Razor." A principle that states that when considering multiple explanations for an observation, one should first investigate the simplest explanation that is consistent with the facts.

question

maximum likelihood

answer

A principle that states that when considering multiple phylogenetic hypotheses, one should take into account the one that reflects the most likely sequence of evolutionary events, given certain rules about how DNA changes over time.

question

gene families

answer

Groups of related genes in an organism's genome.

question

orthologous genes

answer

Homologous genes passed in a straight line from one generation to the next.

question

paralogous genes

answer

Homologous genes that are found in the same genome as a result of gene duplication.

question

Miller and Urey Experiment

answer

Experiment that found that organic molecules can form in a strongly reducing atmosphere.

question

protobionts

answer

Aggregates of abiotically produced molecules surrounded by a membrane.

question

liposomes

answer

Membrane-bound droplets that form when lipids are added to water.

question

radiometric dating

answer

Dating using decay of radioactive isotopes.

question

radioisotopes

answer

Isotopes that have unstable nuclei and undergo radioactive decay.

question

stromatolites

answer

Oldest known fossils formed from many layers of bacteria and sediment.

question

endosymbiotic theory

answer

Ancestors of mitochondria and plastids was prokaryotes thatcame to live in a host cell.

question

serial endosymbiosis

answer

Sequence of endosymbiotic events that led to an ancestral eukaryote.

question

genetic annealing

answer

Horizontal gene transfer between different bacteria and archae.

question

colonies

answer

Collections of autonomously replicating cells.

question

the three-domain system

answer

Domains Bacteria, Archae, and Eukarya.

question

cocci

answer

Spherical bacteria.

question

bacilli

answer

Rod-shaped bacteria.

question

spirilla

answer

Spiral bacteria.

question

plasmolyze

answer

When the membrane shrinks away from the cell wall as a result of water loss.

question

lyse

answer

Cell bursting.

question

peptidoglycan

answer

Cell wall of prokaryotes, but NOT ARCHAEA. Made of a sugar polymer and polypeptide.

question

Gram stain

answer

Used to classify prokaryotes based on cell wall composition. Important for antibiotics; some antibiotics work on one but not the other.

question

Gram-positive bacteria

answer

Bacteria that have simple cell walls with much peptidoglycan.

question

Gram-negative bacteria

answer

Bacteria that have complex cell walls with less peptidoglycan but with lipopolysaccharides. Very toxic and hard to treat.

question

antibiotics

answer

Interfere with production of peptidoglycan; harm bacteria but not eukaryotes.

question

capsule

answer

Covers the cell wall in prokaryotes.

question

pilli

answer

Hollow tubes used to move cells or exchange DNA between bacteria by conjunction.

question

conjugation

answer

In bacteria, the direct transfer of DNA between two cells that are temporarily joined.

question

taxis

answer

Movement toward or away from a stimulus.

question

plasmids

answer

Small rings of DNA found naturally in some bacterial cells in addition to the main bacterial chromosome. Can contain genes for antibiotic resistance, or other "contingency" functions.

question

endospore

answer

A thick-walled protective spore that forms inside a bacterial cell and resists harsh conditions.

question

photoautotrophs

answer

Photosynthetic bacteria.

question

chemoautotrophs

answer

Organisms that use hydrogen sulfide or other chemicals as energy source instead of light.

question

archaea

answer

Domain of unicellular prokaryotes that have cell walls lacking peptidoglycan. Like eukaryotes, DNA contains histone proteins.

question

extremophiles

answer

Archaea that live in extreme environments.

question

thermophiles

answer

Archaea that thrive in very hot environments, such as volcanic springs.

question

methanogens

answer

Archaea that release methane, a greenhouse gas.

question

antibiotic resistance

answer

Resistance evolving rapidly in many species of prokaryotes due to overuse of antibiotics, especially in agriculture.

question

ecology

answer

Study of interactions between organisms and the environment.

question

abiotic factors

answer

Nonliving components of environment.

question

biotic factors

answer

All the plant and animal life of a particular region.

question

biota

answer

Biotic factors.

question

community

answer

All species that inhabit an area.

question

biosphere

answer

The sum of all ecosystems.

question

biogeographic realms

answer

Broad patterns of distribution due to continental drift and barriers such as deserts and mountain ranges.

question

dispersal

answer

Movement of individuals away from centers of high population density or their area of origin.

question

species transplant

answer

Movement of a species to areas where it was previously absent.

question

potential range

answer

An area where an organism could potentially survive and reproduce.

question

actual range

answer

Area an organism actually occupies.

question

climate

answer

Prevailing weather conditions of an area.

question

macroclimate

answer

Patterns on the global, regional and local level.

question

microclimate

answer

Very fine patterns of climate influenced by features of the environment such as shade ares and wind patterns.

question

turnover

answer

Seasonal changes in warm and cool water layers in lakes.

question

biome

answer

Major types of ecological association that occupy broad geographic regions.

question

population density

answer

The size of the population within a particular unit of space.

question

dispersion

answer

Pattern of spacing among individuals.

question

mark-recapture method

answer

A sampling technique used to estimate wildlife populations.

question

immigration

answer

New individuals moving into population. Increases population size.

question

emigration

answer

Movement out of population. Decreases population size.

question

random dispersion

answer

Random spacing of individuals of the same species within an area.

question

clumped dispersion

answer

The most common pattern of dispersion; individuals aggregated in patches.

question

uniform dispersion

answer

The pattern in which individuals are equally spaced throughout a habitat.

question

territoriality

answer

Defense of a space against encroachment by other individuals.

question

demography

answer

Study of vital statistics of a population and how they change over time.

question

life tables

answer

Age-specific summaries of survival patterns of a population.

question

cohort

answer

A group of individuals of the same age.

question

survivorship curves

answer

Graph of the proportion of a cohort still alive at each age.

question

Type I

answer

Curve that shows low death rate at early and mid-life and drops at old age, as seen in humans and large animals.

question

Type II

answer

Curve that represents constant death rate over lifespan small animals and invertebrates.

question

Type III

answer

Curve that drops sharply at the start then levels off once individuals reach a critical age, as seen in organisms that produce large numbers of offspring.

question

reproductive rates

answer

Study of females to determine reproductive output and how it varies with age of female.

question

reproductive table (fertility schedule)

answer

Age-specific summary of reproductive rates in a population.

question

life history

answer

Traits that affect an organism's schedule of reproduction and survival.

question

big-bang reproduction

answer

Species that have only a single reproductive opportunity, such as agave and salmon.

question

repeated reproduction

answer

Species that reproduce over and over.

question

semelparity

answer

Big-bang reproduction.

question

iteroparity

answer

Repeated reproduction.

question

per capita offspring

answer

Average number of offspring produced per individual during a specified period of time.

question

per capita death rate

answer

Expected number of deaths in a population in a specified period of time.

question

reproductive rate

answer

Difference between per capita birth and per capita death rates.

question

zero population growth (ZPG)

answer

When per capita birth and death rates are equal. (r = 0)

question

exponential growth

answer

Population increase under ideal conditions, when r ; 0. Forms a J-shaped curve.

question

logistic growth

answer

When limiting factors restrict size of population to the carrying capacity of the environment. Forms an S-shaped curve.

question

carrying capacity (K)

answer

Maximum population size that a particular environment can support.

question

K - selected species

answer

Life history traits sensitive to population density. Small number of large offspring, extensive parental care, repeated reproduction.

question

r-selected species

answer

Life history traits maximize reproductive success in uncrowded environments. Many small offspring that mature quickly, little if any parental care.

question

density-independent regulation

answer

When birth or death rates do not change with population density.

question

density-dependent regulation

answer

When birth or death rates do change with population density.

question

metapopulation

answer

When many populations are linked.

question

demographic transition

answer

Movement from a high birth rate, high death rate to a low birth rate, low death rate.

question

age structure

answer

Relative number of individuals at each age.

question

infant mortality

answer

Number of infant deaths per thousand live births.

question

life expectancy at birth

answer

Predicted average length of life at birth.

question

ecological footprint

answer

Land and water area appropriated by each nation as a resource to consume or to absorb the waste it generates.

question

interspecific competition

answer

Species compete for a limiting resource. (-/-)

question

competitive exclusion

answer

Strong competition can lead to local elimination of one of the species.

question

Competitive Exclusion Principle

answer

Two species competing for same limiting resource cannot coexist in one place; one species will have an advantage that will eventually lead to competitive exclusion

question

ecological niche

answer

Sum total of a species' use of the biotic and abiotic resources.

question

niche

answer

Sum total of a species' use of the biotic and abiotic resources; an organism's "role".

question

fundamental niche

answer

The niche species could potentially occupy.

question

realized niche

answer

The niche species actually occupies.

question

resource partitioning

answer

Differentiation of niches that enables similar species to coexist.

question

character displacement

answer

Tendency of characteristics to be more divergent in sympatric populations than allopatric populations.

question

cryptic coloration

answer

Camouflage; makes an organism difficult to spot.

question

aposematic coloration

answer

Bright warning colors in animals with a chemical defense.

question

Batesian mimicry

answer

Species mimics the appearance of an unpalatable or harmful.

question

Müllerian mimicry

answer

Two or more unpalatable species resemble each other.

question

endoparasites

answer

Parasites that live within the body of their host.

question

ectoparasites

answer

Parasites that feed on external surface of host.

question

parasitoidism

answer

Insects that lay eggs on or in living host; larvae feed on body of host, eventually killing it. (+/-)

question

mutualism

answer

Interspecific interaction that benefits both species. (+/+)

question

commensalism

answer

Interaction between species that benefits one but neither helps or harms the other. (+/0)

question

coevolution

answer

Reciprocal evolutionary adaptations of two interacting species.

question

keystone species

answer

Not necessarily abundant, but exert a strong control on community structure due to a pivotal ecological role.

question

species diversity

answer

Variety of different kinds of organisms that make up a community.

question

species richness

answer

Total number of different species.

question

relative abundance

answer

The proportion of each species.

question

trophic structure

answer

Feeding relationships between organisms in a community.

question

producer

answer

Autotroph.

question

primary consumer

answer

Herbivore.

question

secondary consumer

answer

Carnivore that eats herbivores.

question

tertiary consumer

answer

Carnivore that eats carnivores.

question

quaternary consumer

answer

Carnivore that eats tertiary consumers.

question

food web

answer

Linked food chains.

question

energy hypothesis

answer

Length of a food chain is limited by the inefficiency of energy transfer.

question

dynamic stability hypothesis

answer

Long food chains are less stable than short chains.

question

dominant species

answer

Species that are the most abundant or have the most biomass.

question

biomass

answer

Total dry mass of all individuals in a population.

question

invasive species

answer

Species generally introduced by humans, that take hold outside of their native range.

question

foundation species

answer

Cause physical changes in environment that affect community structure.

question

facilitators

answer

Foundation species have positive effects on other species.

question

bottom-up model

answer

Unidirectional influence from lower to higher trophic levels. (V --> H)

question

top-down model

answer

Influence moves from top trophic levels to bottom. (V <-- H)

question

biomanipulation

answer

Technique for restoring eutrophic lakes that reduces populations of algae by manipulating higher-level consumers.

question

nonequilibrium model

answer

Communities are constantly changing after being buffeted by disturbances.

question

disturbance

answer

An event, such as storm, fire, flood, drought, overgrazing or human activity, that changes a community and alters resource availability.

question

intermediate disturbance

answer

Moderate levels of disturbance can create conditions that foster greater species diversity.

question

human disturbance

answer

Reduces species diversity in all communities.

question

ecological succession

answer

Gradual recolonization of a disturbed area; species replaced by other species which are replaced by other species.

question

primary succession

answer

Succession that begins in a virtually lifeless area.

question

pioneer species

answer

The first species that colonize new area, such as lichen and mosses.

question

secondary succession

answer

Succession when an existing community has been cleared, but soil left intact.

question

equatorial-polar gradients

answer

Species diversity highest at equator, decreases toward poles.

question

evapotranspiration

answer

Evaporation of water from soil plus transpiration from plants. Correlates with species richness.

question

species-area curve

answer

The larger the geographic area, the greater the number of species.

question

island equilibrium model

answer

Islands great for study due to isolation and limited size; can study species diversity and extinction rates.

question

ecosystem

answer

Consists of all the organisms living in a community as well as all the abiotic factors with which they interact.

question

detritivores

answer

Obtain energy from detritus.

question

detritus

answer

Nonliving organic maters such as remains of dead organisms, feces, fallen leaves, dead wood.

question

primary production

answer

Amount of light energy converted to chemical energy by autotrophs.

question

gross primary production (GPP)

answer

Amount of light energy that is converted to chemical energy by photosynthesis.

question

net primary production (NPP)

answer

Energy used by primary producers for respiration.

question

light limitation

answer

Depth to which light penetrates limits primary production.

question

limiting nutrient

answer

Greater limiting factor than light in oceans and lakes.

question

eutrophication

answer

Sewage and fertilizer runoff adds nutrients to lakes; phytoplankton decreases and cyanobacteria increases.

question

actual evapotranspiration

answer

Annual amount of water transpired by plants and evaporated from landscape.

question

secondary production

answer

Amount of chemical energy in consumers' food that is converted to new biomass.

question

production efficiency

answer

The fraction of energy stored in food that was not used for cell respiration.

question

trophic efficiency

answer

Percentage of production transferred from one trophic level to the next.

question

pyramid of energy

answer

90% of all energy is lost between trophic levels.

question

10% rule

answer

Only 10% of the total energy produced at each trophic level is available to the next level. The amount of energy passed up to the levels of the food pyramid reduces as you go up.

question

pyramids of biomass

answer

Each on this pyramid tier represents standing crop.

question

turnover time

answer

Standing crop biomass compared to production.

question

pyramids of numbers

answer

Number of organisms at each trophic level.

question

Green World Hypothesis

answer

Terrestrial herbivores consume relatively little plant biomass because they are held in check by predators, parasites and disease.

question

critical load

answer

The amount of added nutrient that can be absorbed by plants without damaging ecosystem.

question

biological magnification

answer

Toxins become more concentrated in successive trophic levels.

question

Greenhouse Effect

answer

Carbon dioxide and water vapor in atmosphere trap infrared radiation, re-reflecting it back toward earth.

question

ozone layer

answer

Protective layer in atmosphere that shields earth from UV radiation.

question

conservation biology

answer

Integrates ecology, physiology, molecular biology, genetics and evolutionary biology to conserve biological diversity.

question

restoration ecology

answer

Applies ecological principles in an effort to return degraded ecosystems to conditions as similar as possible to their natural state.

question

endangered species

answer

Species that is in danger of extinction throughout all or a significant portion of its range.

question

threatened species

answer

Species that is likely to become endangered.

question

bioremediation

answer

Use of living organisms such as prokaryotes, fungi, or plants to detoxify polluted ecosystems.

question

biological augmentation

answer

Uses organisms to add essential materials to degraded ecosystems.

question

organelles

answer

Structures specialized to perform distinct processes within a cell.

question

cytosol

answer

The soluble portion of the cytoplasm, which includes molecules and small particles, such as ribosomes, but not the organelles covered with membranes.

question

eukaryotic cells

answer

Contain a nucleus and other organelles that are bound by membranes.

question

cytoplasm

answer

The region of the cell between the cell membrane and the nucleus.

question

plasma membrane

answer

The membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cell's chemical composition.

question

nuclear envelope

answer

Double membrane perforated with pores that control the flow of materials in and out of the nucleus.

question

nuclear lamina

answer

A netlike array of protein filaments lining the inner surface of the nuclear envelope; it helps maintain the shape of the nucleus.

question

chromosomes

answer

A threadlike, gene-carrying structure found in the nucleus. Consists of one very long DNA molecule and associated proteins.

question

chromatin

answer

The readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins.

question

nucleolus

answer

Small, dense region within most nuclei in which the assembly of proteins begins.

question

endomembrane system

answer

A network of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles.

question

vesicle

answer

Small membrane-bound sac that functions in moving products into, out of, and within a cell.

question

smooth ER

answer

Synthesis of lipids, phospholipids and steroid sex hormones-help detoxify drugs and poisons (liver cells).

question

rough ER

answer

A network of interconnected membranous sacs in a eukaryotic cell's cytoplasm; covered with ribosomes that make membrane proteins and secretory proteins.

question

glycoprotein

answer

A protein with one or more carbohydrates covalently attached to it.

question

transport vesicles

answer

Vesicles in transit from one part of the cell to another.

question

Golgi apparatus

answer

Stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum.

question

phagocytosis

answer

Process in which extensions of cytoplasm surround and engulf large particles and take them into the cell.

question

lysosome

answer

A cell organelle that contains digestive enzymes.

question

contractile vacuoles

answer

A membranous sac that helps move excess water out of the cell.

question

mitochondria

answer

The organelles in which nutrients are converted to energy.

question

chloroplasts

answer

Organelles that capture the energy from sunlight and convert it into chemical energy in a process called photosynthesis.

question

peroxisome

answer

A microbody containing enzymes that transfer hydrogen from various substrates to oxygen, producing and then degrading hydrogen peroxide.

question

cristae

answer

Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.

question

thylakoids

answer

Membranous structures within a chloroplast that serve as the site for light harvesting in photosynthesis.

question

stroma

answer

The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water.

question

cytoskeleton

answer

Network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement.

question

cytoplasmic streaming

answer

The motion of cytoplasm in a cell that results in a coordinated movement of the cell's contents.

question

cell wall

answer

Strong layer around the cell membrane in plants, algae, and some bacteria.

question

diffusion

answer

When a substance moves from an area of higher concentration to an area of lower concentration. Due to entropy.

question

osmosis

answer

The diffusion of water through a selectively permeable membrane.

question

dialysis

answer

The diffusion of small solutes through a selectively permeable membrane.

question

passive transport

answer

Transport of a substance across a cell membrane by diffusion. No cell energy required.

question

active transport

answer

When a cell gets materials or excretes them by using its own energy, usually through ATP; going against a concentration gradient.

question

hypertonic

answer

Describes a solution that has a greater concentration of total solute.

question

hypotonic

answer

Describes a solution that has a lesser concentration of total solute.

question

isotonic

answer

Describes solutions that have an equal concentration of total solutes.

question

turgor pressure

answer

The pressure inside of a cell as a cell pushes itself against the cell wall.

question

plasmolysis

answer

This happens when a cell shrinks inside its cell wall while the cell wall remains intact.

question

flaccid

answer

This happens when water moves, but the amount within the cell is constant; no pressure builds.

question

cytolysis

answer

This happens when a cell swells until pressure bursts it, resulting in cell death.

question

crenation

answer

This happens when a cell shrinks and shrivels; can result in cell death if severe.

question

water potential

answer

The physical property predicting the direction in which water will flow, governed by solute concentration and applied pressure.

question

solute potential

answer

This measurement has a maximum value of 0; it decreases as the concentration of a solute increases.

question

pressure potential

answer

This measurement has a minimum value of 0 (when the solution is open to the environment); it increases as pressure increases.

question

selective permeability

answer

A property of a plasma membrane that allows some substances to cross more easily than others.

question

amphipathic

answer

Molecules are said to be this when it has regions that are both hydrophilic and hydrophobic.

question

fluid mosaic model

answer

Structural model of the plasma membrane where molecules are free to move sideways within a lipid bilayer.

question

integral proteins

answer

Integral proteins that span the membrane.

question

transmembrane proteins

answer

Integral proteins that span the membrane.

question

peripheral proteins

answer

The proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane.

question

transport

answer

An exchange of molecules (and their kinetic energy and momentum) across the boundary between adjacent layers of a fluid or across cell membranes.

question

enzymatic activity

answer

A protein built into the membrane with active site exposed.

question

signal transduction

answer

A series of molecular changes that converts a signal on a target cell's surface to a specific response inside the cell.

question

cell-cell recognition

answer

The function of membrane proteins in which some glycoproteins serve as ID tags that are recognized by membrane proteins of other cells.

question

intercellular joining

answer

The function of membrane proteins in which membrane proteins of adjacent cells hook together, as in gap junctions or tight junctions.

question

glycolipids

answer

Membrane carbohydrates that are covalently bonded to lipids.

question

glycoproteins

answer

Membrane carbohydrates that are covalently bonded to proteins.

question

transport protein

answer

A membrane protein, specifically a transport protein, that has a hydrophilic channel that certain molecules or atomic ions use as a tunnel.

question

channel protein

answer

A membrane protein, specifically a transport protein, that has a hydrophilic channel that certain molecules or atomic ions use as a tunnel.

question

aquaporin

answer

A membrane protein, specifically a transport protein, that facilitates the passage of water through channel proteins.

question

carrier protein

answer

A membrane protein, specifically a transport protein, that holds onto molecules and changes their shapes in a way that shuttles them across the membrane.

question

concentration gradient

answer

A difference in the concentration of a substance across a distance.

question

tonicity

answer

The ability of a solution to cause a cell to gain or lose water; depends partly on concentration of nonpenetrating solutes relative to inside of cell.

question

osmoregulation

answer

The control of water balance.

question

turgid

answer

A cell with a cell wall that has a reasonable amount of pressure but is healthy.

question

facilitated diffusion

answer

Passive diffusion that is aided by transport proteins, but that does not require cellular energy.

question

membrane potential

answer

The voltage of a plasma membrane.

question

electrochemical gradient

answer

The combination of forces that acts on membrane potential.

question

gated channel

answer

A protein channel in a cell membrane that opens or closes in response to a particular stimulus.

question

electrogenic pump

answer

A transport protein that generates voltage across a membrane, causing a net separation in charge.

question

proton pump

answer

An electrogenic pump that works largely with H+ ions.

question

cotransport

answer

The coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient.

question

exocytosis

answer

Occurs when a cell secretes certain biological molecules by the fusion of vesicles with the plasma membrane.

question

endocytosis

answer

Occurs when a cell takes in biological molecules and particulate matter by forming new vesicles from the plasma membrane.

question

phagocytosis

answer

Process in which extensions of cytoplasm surround and engulf large particles and take them into the cell.

question

pinocytosis

answer

A type of endocytosis in which the cell "gulps" droplets of fluid into tiny vesicles.

question

receptor-mediated

answer

A type of endocytosis in which the cell acquires bulk quantities of specific substances, even though they may not be very concentrated in the extracellular fluid.

question

ligand

answer

Any molecule that bonds specifically to a receptor site of another molecule.

question

signal transduction pathway

answer

The process by which a signal on a cell's surface is converted into a specific cellular response.

question

local regulators

answer

These regulators influence cells in the vicinity of them.

question

hormones

answer

Circulating chemical signals that are formed in specialized cells, travels in body fluids, and act on specific target cells.

question

ligand

answer

Any molecule that bonds specifically to a receptor site of another molecule.

question

protein kinase

answer

The enzyme that transfers phosphate groups from ATP to protein.

question

adenylyl cyclase

answer

Converts ATP to cyclic AMP in response to an extracellular signal.

question

protein phosphatases

answer

Enzymes that can rapidly remove phosphate groups from proteins.

question

second messengers

answer

Small, non-protein water soluble molecules or ions that send messages throughout the cells by diffusion.

question

inositol triphosphate

answer

Produced by cleavage of a certain kind of phospholipid in the plasma membrane.

question

scaffolding proteins

answer

A type of large relay protein to which several other relay proteins are simultaneously attached to increase the efficiency of signal transduction.

question

anatomy

answer

Study of the structure of an organism.

question

physiology

answer

Study of the functions an organism performs.

question

tissues

answer

Groups of cells with a common structure and function.

question

epithelial tissue

answer

Tissue that covers outside of the body and lines organs and cavities.

question

glandualar epithelia

answer

Tissue that absorbs or secretes chemical solutions.

question

mucous membrane

answer

Membrane that secretes mucus that lubricates the surface of organs and keeps them moist.

question

simple epithelium

answer

Single layer of cells.

question

stratified epithelium

answer

Multiples tiers of cells.

question

cubiodal epithelium

answer

Dice-shaped cells.

question

columnar epithelium

answer

Cells shaped like bricks standing on end.

question

squamous epithelium

answer

Cells that are like floor tiles.

question

connective tissue

answer

Tissue that functions mainly to bind and support other tissues.

question

collagenous fibers

answer

Fibers made of collagen.

question

elastic fibers

answer

Fibers made of elastin.

question

reticular fibers

answer

Fibers made of collagen fibers that are very thin and branched. Forma tightly woven fabric that joins connective tissue to adjacent tissues.

question

fibroblasts

answer

In connective tissue, cells that secrete the proteins of the fibers.

question

macrophages

answer

Amoeboid cells that roam connective tissue and engulf foreign particles and debris of dead cells.

question

muscle tissue

answer

Tissue made of cells capable of contracting.

question

nervous tissue

answer

Tissue that senses stimuli and transmits signals.

question

basement membrane

answer

Cells at the base of an epithelial layer are attached to this.

question

loose connective tissue

answer

Tissue that binds epithelia to underlying tissues and holds organs in place. Contains collagenous, elastic, and recticular fibers.

question

fibrous connective tissue

answer

Dense tissue, large number of collagen fibers organized into parallel bundles. Includes ligaments and tendons.

question

bone

answer

Mineralized connective tissue.

question

osteoblasts

answer

Bone-forming cells.

question

blood

answer

Connective tissue made of plasma, erythrocytes, leukocytes, and platelets.

question

adipose tissue

answer

Tissue that stores fat.

question

tendons

answer

Attach muscles to bones.

question

ligaments

answer

Join bones to bones at joints.

question

cartilage

answer

Made of collagenous fibers in matrix of chondroitin sulfate.

question

chondrocytes

answer

Cells that secrete cartilage.

question

skeletal muscle

answer

Muscle that is striated, multinucleated.

question

smooth muscle

answer

Muscle that is not striated, is single nucleated.

question

cardiac muscle

answer

Muscle that is branched, striated, singe nucleated.

question

organs

answer

Tissues are organized into:, group of tissues that work together to perform closely related functions.

question

mesenteries

answer

Sheets of connective tissue in moist or fluid-filled body cavities.

question

thoracic cavity

answer

cavity housing lungs and heart

question

abdominal cavity

answer

Cavity housing intestines.

question

bioenergetics

answer

Flow of energy through an animal. Limits its behavior, growth, reproduction.

question

metabolic rate

answer

Amount of energy an animal uses in a unit of time; the sum of all the energy-requiring biochemical reactions.

question

endothermic

answer

Animals that are warmed mostly by heat generated by metabolism.

question

exothermic

answer

Animals that gain heat mostly from external sources.

question

basal metabolic rate (BMR)

answer

The metabolic rate of a nongrowing, resting, fasting, nonstressed endotherm.

question

standard metabolic rate (SMR)

answer

The metabolic rate of a resting, fasting, nonstressed ectotherm.

question

interstitial fluid

answer

Watery, internal environment of vertebrates.

question

homeostasis

answer

"Steady state" or "constant internal milieu".

question

regulator

answer

An animal that uses internal control mechanisms to moderate internal change in the face of external fluctuation.

question

conformer

answer

An animal that allows its internal condition to vary with certain external changes.

question

negative feedback

answer

A type of regulation that responds to a change in conditions by initiating responses that will counteract the change. Maintains a steady state.

question

positive feedback

answer

A type of regulation that responds to a change in conditions by initiating responses that will amplify the change. Takes organism away from a steady state.

question

thermoregulation

answer

Process of maintaining an internal temperature within a tolerable range.

question

vasodialation

answer

Increases in the diameter of superficial blood vessels; cools the body.

question

vasoconstriction

answer

Reduces blood flow and heat transfer by decreasing the diameter of superficial blood vessels.

question

countercurrent heat exchanger

answer

In ectotherms, a circulatory adaptation that is an arrangement of blood vessels that warm or cool the blood.

question

nonshivering thermogenesis (NST)

answer

When hormones cause mitochondria to produce heat instead of ATP in some mammals.

question

brown fat

answer

Tissue in neck and between shoulders of some mammals that is specialized for rapid heat production.

question

acclimatization

answer

Adjusting to a new range of environmental temperatures.

question

heat-shock proteins

answer

Proteins that help maintain integrity of other proteins that would normally be denatured in extreme heat.

question

torpor

answer

Physiological state in which activity is low and metabolism decreases.

question

hibernation

answer

Long-term torpor that is an adaptation to winter cold and food scarcity.

question

estivation

answer

Summer torpor. Enables animals to survive long periods of high temperatures and scarce water supplies.

question

daily torpor

answer

in small mammals and birds, daily lowering of metabolism that allows them to survive on stored energy

question

metabolic pathway

answer

Begins with a specific molecule, which is then altered in a series of defined steps, resulting in a certain product.

question

catabolic pathways

answer

Metabolic pathways that release energy by breaking down complex molecules into simpler compounds.

question

anabolic pathways

answer

Metabolic pathways that consume energy to build complicated molecules from simpler ones.

question

bioenergenetics

answer

The study of how organisms manage their energy resources.

question

kinetic energy

answer

Energy associated with relative motion of objects.

question

thermal energy

answer

Kinetic energy associated with the random movement of molecules or atoms.

question

potential energy

answer

Occurs when an object is not moving, but may still posses energy.

question

first law of thermodynamics

answer

Energy can be transferred and transformed, but it cannot be created or destroyed.

question

entropy

answer

A measure of disorder or randomness.

question

second law of thermodynamics

answer

Every energy transfer or transformation increases the entropy of the universe.

question

free energy

answer

Measures the portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system, as in a living cell.

question

endergonic reaction

answer

Reaction that absorbs free energy from its surroundings.

question

exergonic reaction

answer

Reaction that proceeds with a net release of free energy.

question

energy coupling

answer

The use of an exergonic process to drive an endergonic one.

question

ATP (adenosine triphosphate)

answer

Composed of a sugar ribose, nitrogenous base adenine, and a chain of three phosphate groups bonded to it.

question

phosphorylation

answer

The metabolic process of introducing a phosphate group into an organic molecule.

question

catalyst

answer

A chemical agent that speeds up a reaction without being consumed by the reaction.

question

enzyme

answer

A catalytic protein.

question

activation energy

answer

The amount of energy needed to push the reactants over an energy barrier.

question

enzyme-substrate complex

answer

When an enzyme binds to its substrate, it forms:

question

active site

answer

A pocket or groove on the surface of the enzyme.

question

induced fit

answer

Brings chemical groups of the active site into positions that enhance their ability to catalyze the chemical reaction.

question

cofactor

answer

Non-protein helpers that may be bound tightly to the enzyme as a permanent resident, or may bind loosely and reversibly along with the substrate.

question

coenzyme

answer

If the cofactor is an organic molecule.

question

competitive inhibitors

answer

Reduce the productivity of enzymes by blocking substrates from entering active sites.

question

noncompetitive inhibitors

answer

Impede enzymatic reactions by binding to another part of the enzyme (other than the active site).

question

allosteric regulation

answer

When a protein's function at one site is affected by the binding of a regulatory molecule to a separate site.

question

cooperativity

answer

It amplifies the response of enzymes to substrates.

question

feedback inhibition

answer

A metabolic pathway is switched off by the inhibitory binding of its end product to an enzyme that acts early in the pathway.

question

fermentation

answer

A partial degradation of sugars that occur without the use of oxygen.

question

cellular respiration

answer

When oxygen is consumed as a reactant along with the organic fuel.

question

redox reactions

answer

When there is a transfer of one or more electrons from one reactant to another.

question

oxidation

answer

Loss of electrons.

question

reduction

answer

Gain of electrons.

question

reducing agent

answer

A reduces B, which accepts the donated electrons.

question

oxidizing agent

answer

B oxidizes A by removing A's electrons.

question

electron transport chain

answer

Breaks the fall of electrons to oxygen in several energy-releasing steps.

question

glycolosis

answer

Breaking glucose into two molecules of a compound called pyruvate.

question

citric acid cycle

answer

Completes the breakdown of glucose by oxidizing a derivative of pyruvate to carbon dioxide.

question

oxidative phosphorylation

answer

When energy is released at each step of the chain is stored in a form the mitochondrion can use to make ATP.

question

substrate-level phosphorylation

answer

When an enzyme transfers a phosphate group from a substrate molecule.

question

acetyl-CoA

answer

Is formed when pyruvate first enters into the mitochondria via active transport.

question

ATP synthase

answer

The enzyme that make ATP from ADPand inorganic phosphate.

question

chemiosmosis

answer

When energy is stored in the form of a hydrogen ion gradient across a membrane which is used to drive cellular work.

question

proton-motive force

answer

Emphasizes the capactiy of the gradient to preform work.

question

anaerobic

answer

Occurs by fermentation, which generate ATP solely by substrate-level phosphorylation.

question

alcohol fermentation

answer

When pyruvate is converted to ethanol in 2 steps.

question

lactic acid fermetation

answer

When pyruvate is reduced directly by NADH to form lactic as am end product, with no release of carbon dioxide.

question

facultative anaerobes

answer

Can make enough ATP to survive using using fermentation or respiration.

question

innate immunity

answer

Immunity that is present before exposure and effective from birth. Responds to a broad range of pathogens.

question

acquired immunity

answer

Immunity that is present only after exposure and is highly specific.

question

lymphocytes

answer

White blood cells.

question

antibodies

answer

Protein that is produced by lymphocytes and that attaches to a specific antigen.

question

neutrophils

answer

Most abundant white blood cell., The most abundant type of white blood cell. Phagocytic and tend to self-destruct as they destroy foreign invaders, limiting their life span to a few days.

question

complement system

answer

A group of about 30 blood proteins that may amplify the inflammatory response, enhance phagocytosis, or directly lyse extracellular pathogens.

question

interferon

answer

Protein produced by cells in response to being infected by a virus; helps other cells resist the virus.

question

inflammtory response

answer

Innate response with the purpose of containing a site of damage, localizing the response, eliminating the invader and restore tissue function.

question

histamine

answer

Chemical stored in mast cells that triggers dilation and increased permeability of capillaries.

question

natural killer (NK) cells

answer

These cells kill cancer cells and cells infected with viruses. They bind to their targets and deliver a lethal burst of chemicals to produce holes in the target cell's membrane leading to its destruction.

question

antigen

answer

Any foreign molecule that is specifically recognized by lymphocytes and elicits an immune response.

question

epitope

answer

Small, accessible portion of an antigen that can be recognized.

question

B lymphocytes (B cells)

answer

Lymphocyte that matures in the bone marrow and secretes antibodies.

question

T lymphocytes (T cells)

answer

Lymphocyte that matures in the thymus and acts directly against antigens in cell-mediated immune responses.

question

immunoglobulins

answer

Secreted antibodies.

question

antigen presentation

answer

The process by which an MHC molecule binds to a fragment of an intracellular protein antigen and carries it to the cell surface, where it is displayed and can be recognized by a T cell.

question

thymus

answer

Gland in the thoracic cavity above the heart where T lymphocytes mature.

question

memory cells

answer

General term for lymphocytes that are responsible for immunological memory and protective immunity.

question

primary immune response

answer

Immune response the first time the body is exposed to a particular antigen. Does not peak until 10-17 days after exposure.

question

secondary immune response

answer

Immune response after the body has already been exposed to a specific antigen. Response is faster, of greater magnitude, and more prolonged.

question

humoral immune response

answer

The branch of acquired immunity that involves the activation of B cells and that leads to the production of antibodies, which defend against bacteria and viruses in body fluids.

question

cell-mediated immune response

answer

The branch of acquired immunity that involves the activation of cytotoxic T cells, which defend against infected cells.

question

helper T cells

answer

Activate macrophages, B cells and T cells.

question

active immunity

answer

A form of acquired immunity in which the body produces its own antibodies against disease-causing antigens.

question

passive immunity

answer

Immunity conferred by transferring antibodies from an individual who is immune to a pathogen to another individual.

question

immunization

answer

The deliberate exposure of a pathogen to produce memory cells.

question

Rh factor

answer

Refers to the presence or absence of the Rh antigen on red blood cells.

question

graft versus host reaction

answer

When lymphocytes in donated bone marrow react against the recipient.

question

anaphylactic shock

answer

A severe reaction that occurs when an allergen is introduced to the bloodstream of an allergic individual. Characterized by bronchoconstriction, labored breathing, widespread vasodilation, circulatory shock, and sometimes sudden death.

question

autoimmune diseases

answer

Diseases caused when the immune system loses tolerance for self and turns against certain molecules in the body.

question

Acquired Immunodeficiency Syndrome (AIDS)

answer

The most advanced, and fatal, stage of an HIV infection.

question

B cell receptor

answer

The antigen receptor on B cells: a Y-Shaped, membrane-bound molecule consisting of two identical heavy chains and two identical light chains linked by disulfide bridges and containing two antigen-binding sites.

question

T cell receptor

answer

Antigen receptors on a T cell. Unlike antibodies, T cell receptors are never produced in a secreted form.

question

major histocompatibility compex (MHC)

answer

Binds to a fragment of an antigen within a cell and presents it on the surface of the membrane.

question

cytotoxic T cells or "killer T cells"

answer

T cells that directly attack infecting organisms; these cells attack antigen labeled foreign or host tissue.

question

hormone

answer

The secretion of an endocrine gland that is transmitted by the blood to the tissue on which it has a specific effect.

question

endocrine system

answer

The system of glands that produce endocrine secretions that help to control bodily metabolic activity.

question

edocrine glands

answer

Glands that secrete chemicals called hormones directly into the bloodstream.

question

neurosecretory cells

answer

Neurons that secrete neurohormone rather than neurotransmitter.

question

paracrine signaling

answer

Signal released from a cell has an effect on neighboring cells.

question

cytokines

answer

Chemicals released by the immune system communicate with the brain.

question

growth factors

answer

Factors that stimulate the cell to divide.

question

nitric oxide (NO)

answer

Local regulator that regulates blood oxygen levels, A gas produced by many types of cells that functions as a local regulator and as a neurotransmitter.

question

prostaglandins

answer

Modified fatty acids that are produced by a wide range of cells.

question

endocrine signaling

answer

Specialized cells release hormone molecules into vessels of the circulatory system, by which they travel to target cells in other parts of the body.

question

insulin

answer

Hormone produced by the pancreas that helps to decrease blood sugar.

question

glucagon

answer

The antagonist of insulin that helps increase blood sugar. It stimulates the liver to break down glycogen into glucose.

question

cell differentiation

answer

Cell specialization in structure and function.

question

morphogenesis

answer

The process by which an organism takes shape and the differentiated cells occupy their appropriate locations.

question

fate maps

answer

A labor-intensive study to produce useful territorial diargams of embryonic development.

question

pattern formation

answer

The development of a spatial organization of tissues and organs.

question

positional information

answer

The molecular cues that control pattern formation.

question

sensory neurons

answer

Neurons that carry incoming information from the sense receptors to the central nervous system.

question

motor neurons

answer

Neurons that carry outgoing information from the central nervous system to the muscles and glands.

question

Central Nervous System (CNS)

answer

Includes the brain and spinal cord.

question

Peripheral Nervous System (PNS)

answer

The sensory and motor neurons that connect the CNS to the rest of the body.

question

cell body

answer

Contains most of a neuron's organelles and its nucleus.

question

dendrites

answer

Highly branched extensions that receive signals from other neurons.

question

axon

answer

Long nerve fiber that conducts away from the cell body of the neuron.

question

axon hillock

answer

Cone shaped region of an axon where it joins the cell body.

question

synapse

answer

The junction between two neurons or between a neuron and a muscle.

question

synaptic terminal

answer

A bulb at the end of an axon in which neurotransmitter molecules are stored and released.

question

neurotransmitters

answer

Chemical messengers that cross the synaptic gaps between neurons.

question

presynaptic cell

answer

The transmitting neuron in a synapse.

question

postsynaptic cell

answer

The neuron, muscle, or gland cell that receives the signal from a neuron.

question

membrane potential

answer

The voltage across a cell's plasma membrane.

question

resting potential

answer

The membrane potential of a neuron that is at rest.

question

depolarization

answer

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.

question

voltage-gated ion channels

answer

Channels that open or close in response to a change in the membrane potential.

question

action potential

answer

A neural impulse; a brief electrical charge that travels down an axon.

question

threshold potential

answer

The minimum membrane potential that must be reached in order for an action potential to be generated.

question

myelin sheath

answer

A layer of electrical insulation that surrounds the axon.

question

oligodendrocytes

answer

Type of glial cell in the CNS that wrap axons in a myelin sheath.

question

Schwann cells

answer

Type of glia in the PNS, Supporting cells of the peripheral nervous system responsible for the formation of myelin.

question

nodes of Ranvier

answer

Gaps in the myelin sheath to which voltage-gated sodium channels are confined.

question

synaptic vesicles

answer

Membrane-bounded compartments in which synthesized neurotransmitters are kept.

question

synaptic cleft

answer

The narrow gap that separates the presynaptic neuron from the postsynaptic cell.

question

acetylcholine

answer

Common vertebrate neurotransmitter, especially in neuromuscular junctions.

question

serotonin

answer

A neurotransmitter that affects hunger,sleep, arousal, and mood.

question

dopamine

answer

Important neurotransmitter in the CNS that acts on the sympathetic nervous system.

question

epinephrine

answer

Neurotransmitter secreted by the adrenal medulla in response to stress. Also known as adrenaline.

question

norepinephrine

answer

A precursor of epinephrine that is secreted by the adrenal medulla and also released at synapses.

question

GABA

answer

An inhibitory neurotransmitter in the brain.

question

glutamate

answer

The most common neurotransmitter in the brain. Excitatory.

question

endorphins

answer

Natural analgesics that decrease pain perception.

question

neuron

answer

Structural and functional unit of nervous system.

question

effector cells

answer

Muscle cells or gland cells that carry out the body's response to stimuli.

question

astrocytes

answer

Provide structural and metabolic support for neurons.

question

glial cells

answer

Cells in the nervous system that support, nourish, and protect neurons.

question

ganglion

answer

A cluster of nerve cell bodies, often of similar function, located in the PNS.

question

white matter

answer

Whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths.

question

grey matter

answer

The portions of the central nervous system that are abundant in cell bodies of neurons rather than axons. Unmyelinated.

question

autonomic nervous system

answer

The part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands.

question

sympathetic division

answer

The part of the autonomic nervous system that arouses the body to deal with perceived threats.

question

parasympathetic division

answer

A branch of the autonomic nervous system that maintains normal body functions; it calms the body ever conserves energy.

question

enteric division

answer

One of three divisions of the autonomic nervous system; consists of networks of neurons in the digestive tract, pancreas, and gallbladder.

question

cerebrum

answer

Largest part of the brain; responsible for voluntary muscular activity, vision, speech, taste, hearing, thought, and memory.

question

forebrain

answer

The largest and most complicated region of the brain, including the thalamus, hypothalamus, limbic system, and cerebrum.

question

midbrain

answer

Region between the hindbrain and the forebrain; it is important for hearing and sight.

question

hindbrain

answer

The posterior portion of the brain including cerebellum and brainstem.

question

cerebral cortex

answer

Interconnected neural cells that covers the cerebral hemispheres; the body's ultimate control and information-processing center.

question

brainstem

answer

The oldest part and central core of the brain, responsible for automatic survival functions.

question

medulla oblongata

answer

Contains centers that control several visceral functions, including breathing, heart and blood vessel activity, swallowing, vomiting, and digestion.

question

recticular formation

answer

Registers and controls activity level, increases excitement, and helps generate sleep.

question

cerebellum

answer

The "little brain" attached to the rear of the brainstem; it helps coordinate voluntary movement and balance.

question

thalamus

answer

Major input center for sensory information going to the cerebrum and the main output center for motor information leaving the cerebrum.

question

circadian rhythms

answer

The 24-hour biological cycles found in humans and many other species.

question

biological clock

answer

An innate mechanism in living organisms that controls the periodicity of many physiological functions.

question

cerebral hemispheres

answer

The right and left halves of the cerebrum.

question

corpus callosum

answer

Nerves that enable communication between the right and left cerebral hemispheres.

question

behavior

answer

The way an organism reacts to changes in its internal condition or external environment.

question

proximate questions

answer

Address environmental stimuli, genetic, physiological, and anatomical causes of a behavior.

question

ultimate questions

answer

Address evolutionary significance of a behavior.

question

ethology

answer

The scientific study of how animals behave, particularly in natural environments.

question

fixed action patterns (FAP)

answer

A sequence of unlearned behavioral acts that is unchangeable and usually carried to completion.

question

sign stimulus

answer

External sensory stimulus that triggers a fixed action pattern.

question

imprinting

answer

Includes both learning and innate components, generally irreversible.

question

sensitive period

answer

A limited phase in an animal's development that is the only time when certain behaviors can be learned.

question

innate behavior

answer

A behavior that is developmentally fixed.

question

kinesis

answer

A simple change in activity or turning rate in response to a stimuli.

question

taxis

answer

Automatic, oriented movement toward or away from some stimuli.

question

migration

answer

Relatively long-distance movement of individuals, usually on a seasonal basis.

question

signal

answer

A behavior that causes change in another's behavior.

question

communication

answer

Signals among animals that include sounds, odors, visual displays, and touches that produce responses.

question

learning

answer

The modification of behavior based on specific experiences.

question

habituation

answer

A loss of responsiveness to stimuli that convey little or no information.

question

spatial learning

answer

The modification of behavior based on experience with the spatial structure of the environment.

question

cognitive maps

answer

An internal representation of the spatial relationships between objects in an animal's surroundings.

question

associative learning

answer

The ability of animals to associate one feature with another.

question

classical conditioning

answer

An arbitrary stimulus is associated with an award or punishment.

question

operant conditioning

answer

Learning based on the consequences of responding.

question

cognition

answer

The ability of an animal's nervous system to perceive, store, process, and use information gathered by sensory receptors.

question

foraging

answer

Behavior associated with recognizing, searching for, capturing, and consuming food.

question

optimal foraging theory

answer

Views foraging behavior as a compromise between benefits of nutrition and costs of obtaining food.

question

promiscuous

answer

No strong pair bonds or lasting relationships.

question

monogamous

answer

One male mating with one female.

question

polygamous

answer

An individual of one sex mating with several of the other.

question

polygyny

answer

One male, several females.

question

polyandry

answer

One female, several males.

question

agonistic behavior

answer

Competition that determines who wins a prize, such as food or mates.

question

game theory

answer

Evaluates alternate strategies when outcome depends not only on each individual's strategy but also that of others.

question

altruism

answer

Behavior that benefits another without benefiting oneself.

question

inclusive fitness

answer

The total effect an individual has on proliferating its genes by producing its own offspring and by providing aid that enables other close relatives to increase the production of their offspring.

question

coefficient of relatedness

answer

Probability that if two individuals share common parent or ancestor, a particular gene present in one will be present in other.

question

Hamilton's rule

answer

when C < r x B C = cost to the altruistic party r = genetic relatedness B = fitness benefit to recipient of altuism

question

kin selection

answer

Natural selection that favors altruistic behaviors by enhancing reproductive success of relatives.

question

social learning

answer

Learning through observing others.

question

culture

answer

A system of information transfer through influential social learning or teaching.

question

mate choice copying

answer

Individuals in a population copy mate choice of others.

question

cell division

answer

The process in reproduction and growth by which a cell divides to form daughter cells.

question

genome

answer

The ordering of genes in a haploid set of chromosomes of a particular organism.

question

binary fission

answer

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size.

question

somatic cell

answer

Any of the cells of a plant or animal except the reproductive cells.

question

chromosomes

answer

Threadlike structures made of DNA molecules that contain the genes.

question

chromatin

answer

The readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins.

question

sister chromatids

answer

Identical copies of a chromosome; full sets of these are created during the S subphase of interphase.

question

centromere

answer

The region of the chromosome that holds the two sister chromatids together during mitosis.

question

centriole

answer

In animal cells, a cytoplasmic organelle that organizes the mitotic spindle fibers during cell reproductions.

question

cell cycle

answer

Series of events that cells go through as they grow and divide.

question

mitosis

answer

Cell division in which the nucleus divides into nuclei containing the same number of chromosomes.

question

M phase

answer

Mitosis and cytokinesis.

question

cytokinesis

answer

Division of the cytoplasm to form two separate daughter cells.

question

S phase

answer

The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.

question

G1 phase

answer

The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins.

question

G2 phase

answer

The second growth phase of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

question

interphase

answer

Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases.

question

mitotic spindle

answer

An assemblage of microtubules and associated proteins that is involved in the movements of chromosomes during mitosis.

question

centrosome

answer

A structure in animal cells containing centrioles from which the spindle fibers develop.

question

kinetochore microtubules

answer

Connects the centrosome with the kinetochore in the centromere region of the chromosome.

question

kinetochore

answer

A specialized region on the centromere that links each sister chromatid to the mitotic spindle.

question

asters

answer

Microtubules and fibers that radiate out from the centrioles.

question

metaphase plate

answer

Plane midway between the two poles of the cell where chromosomes line up during metaphase.

question

cleavage furrow

answer

The first sign of cleavage in an animal cell; a shallow groove in the cell surface near the old metaphase plate.

question

cell plate

answer

A double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis.

question

density dependent inhibition

answer

The arrest of cell division that occurs when cells grown in a laboratory dish touch one another.

question

growth factors

answer

Regulatory proteins that ensure that the events of cell division occur in the proper sequence and at the correct rate.

question

restriction point

answer

A point of no return in the cell cycle; once this point passes, a cell is committed to a full round of the cell cycle.

question

Cdk

answer

Complex of cyclin and kinase.

question

MPF

answer

A cyclin-Cdk complex that causes the cell to move from interphase into mitosis.

question

cancer

answer

Any malignant growth or tumor caused by abnormal and uncontrolled cell division.

question

cleavage

answer

The process of cytokinesis in animal cells, characterized by pinching of the plasma membrane; specifically.

question

allele

answer

One of the alternative forms of a gene that governs a characteristic, such as hair color.

question

alteration of generations

answer

The alteration of two or more different forms in the life cycle of a plant or animal.

question

asexual reproduction

answer

One parent produces a genetically identical offspring by mitosis.

question

autosomes

answer

Chromosomes that are not directly involved in determining the sex of an individual.

question

chiasmata

answer

X-shaped regions where crossing over occurred.

question

clone

answer

An identical genetically individual of the parent

question

crossing over

answer

Nonsister chromatids exchanging DNA segments.

question

diploid cell

answer

Has two sets of chromosomes.

question

fertilization

answer

Union of gametes.

question

gametes

answer

A haploid cell such as an egg or sperm that unite during sexual reproduction to produce a diploid zygote.

question

gametophyte

answer

The stage in the life cycle of a plant in which the plant produces gametes, or sex cells.

question

genes

answer

Units of heredity made up of DNA.

question

genetics

answer

Scientific study of heredity and variation.

question

haploid

answer

One set of chromosomes.

question

heredity

answer

Transmission of traits from one generation to the next.

question

homologous chromosomes

answer

Pair of chromosomes that are the same size, same appearance and same genes.

question

independent assortment

answer

The random distribution of the pairs of genes on different chromosomes to the gametes.

question

karyotype

answer

Photograph of chromosomes grouped in order and in pairs.

question

life cycle

answer

All of the events in the growth and development of an organism until the organism reaches sexual maturity.

question

locus

answer

The specific site of a particular gene on its chromosome.

question

nonsister chromatids

answer

Different chromatids (maternal and paternal) of the same chromosome.

question

recombinant chromosomes

answer

Chromosomes that carry genes from each parent.

question

sex chromosomes

answer

X and Y chromosomes.

question

sexual reproduction

answer

When two parents give unique combination of genes to offspring.

question

spores

answer

Produced by meiosis. Grow into haploid organisms by mitosis.

question

sporophyte

answer

Diploid, or spore-producing, phase of an organism. Makes haploid spores by meiosis.

question

synapsis

answer

Homologous chromosomes pair up, aligned gene by gene.

question

tetrad

answer

A pair of chromosomes form tetrads made up of four chromatids.

question

zygote

answer

Fertilized egg. Carries one set of chromosomes from each parent.

question

variation

answer

Is demonstrated by the differences in appearance that offspring show from parents and siblings.

question

character

answer

A heritable feature that varies among individuals.

question

trait

answer

Each variant of a character.

question

true-breeding

answer

Organisms that, when reproducing, create offspring of all the same variety.

question

hybridization

answer

The crossing of two true-breeding parents.

question

P generation

answer

The name for the true-breeding parents.

question

F1 Generation

answer

The hybrid offspring of true-breeding parents.

question

F2 Generation

answer

After the self-pollenization of the F1 generation, this is produced.

question

The Law of Segregation

answer

Two alleles separate during gamete formation and end up in different gametes because they are on on homologous chromosomes.

question

dominant allele

answer

An allele whose trait always shows up in the organism when the allele is present.

question

recessive allele

answer

An allele that is masked when a dominant allele is present

question

Punnett square

answer

A diagram for predicting the allele composition of offspring from a cross between individuals of known genetic makeup.

question

homozygous

answer

An organism having a pair of identical alleles for a character, either dominant or recessive.

question

phenotype

answer

An organism's traits.

question

genotype

answer

An organism's genetic makeup.

question

testcross

answer

The result of breeding a recessive homozygote with an organism of dominant phenotype but unknown genotype.

question

monohybrids

answer

Parents that are heterozygous for one character.

question

dihybrids

answer

Parents that are heterozygous for two characters.

question

multiplication rule

answer

To determine the probability, we multiply the probability of one event by the probability of another.

question

addition rule

answer

Considering mutually exclusive events, the probability of both occurring is the sum of the probabilities of each event.

question

complete dominance

answer

When the phenotypes of the heterozygote and dominant homozygote are indistinguishable.

question

codominance

answer

When which the phenotypes of both alleles are exhibited in the heterozygote.

question

incomplete dominance

answer

Creates a blended phenotype; one allele is not completely dominant over the other.

question

Tay-Sachs disease

answer

A human genetic disease caused by a recessive allele that leads to the accumulation of certain lipids in the brain. Seizures, blindness, and degeneration of motor and mental performance usually become manifest a few months after birth.

question

quantitative characters

answer

Characters that vary in the population along a continuum (in gradations).

question

polygenic inheritance

answer

An additive effect of two or more genes on a single phenotypic character.

question

pedigree

answer

A diagram that shows the occurrence of a genetic trait in several generations of a family.

question

cystic fibrosis

answer

A genetic disorder that is present at birth and affects both the respiratory and digestive systems.

question

sickle-cell disease

answer

Genetic disorder in which red blood cells have abnormal hemoglobin molecules and take on an abnormal shape.

question

Huntington's disease

answer

Genetic disorder that causes progressive deterioration of brain cells. caused by a dominant allele. symptoms do not appear until about the age of 30.

question

aminocentesis

answer

Prenatal diagnostic technique that involves inserting a needle to obtain a sample of amniotic fluid that surrounds the fetus.

question

chorionic villus sampling (CVS)

answer

Prenatal diagnostic technique that involves taking a sample of tissue from the chorion.

question

chromosome theory of inheritance

answer

According to this theory, genes are carried from parents to their offspring on chromosomes.

question

XY system

answer

A sex determination system in which females have two of the same kind of sex chromosome and males have two different ones.

question

XO system

answer

A sex determination system in some insects in which O stands for the absence of a sex chromosome. Females are XX, Males are XO. Males produce two classes of sperm: X sperm and sperm with no chromosome. The sperm determines the sex of the offspring.

question

ZW system

answer

A sex determination system in fish, butterflies, birds where males are ZZ and Females are ZW. The egg determines the sex of the offspring.

question

haplo diploid system

answer

A sex determination system in most species of bees and ants in which there are no sex chromosomes. Females develop from fertilized eggs (diploid) and males develop from unfertilized eggs (haploid).

question

sex linked genes

answer

Genes located on the sex chromosomes.

question

X linked genes

answer

Genes found on the X chromosome.

question

Duchenne muscular dystrophy

answer

A human genetic disease caused by a sex-linked recessive allele; characterized by progressive weakening and a loss of muscle tissue.

question

barr body

answer

A dense body formed from a deactivated X chromosome.

question

hemophilia

answer

An X-linked recessive disorder in which blood fails to clot properly, leading to excessive bleeding if injured.

question

linked genes

answer

Genes located on the same chromosome that tend to be inherited together in genetic crosses.

question

genetic recombination

answer

The regrouping of genes in an offspring that results in a genetic makeup that is different from that of the parents.

question

parental types

answer

Offspring with a phenotype that matches one of the parental phenotypes.

question

recombinant types

answer

Offspring who have inherited new combinations of genes and have phenotypes that don't match either parental phenotypes.

question

crossing over

answer

Process in which homologous chromosomes exchange portions of their chromatids during meiosis.

question

genetic map

answer

An ordered list of the genetic loci along a particular chromosome.

question

linkage map

answer

A genetic map based on recombination frequencies.

question

map units

answer

A measurement of the distance between genes; one map unit is equivalent to a 1 percent recombination frequency.

question

nondisjunction

answer

Error in meiosis in which homologous chromosomes fail to separate.

question

aneuploidy

answer

Abnormal number of chromosomes.

question

monosomic

answer

A chromosomal condition in which a particular cell has only one copy of a chromosome, instead of the normal two.

question

trisomic

answer

A chromosomal condition in which a particular cell has an extra copy of one chromosome, instead of the normal two.

question

inversion

answer

A type of mutation in which the order of the genes in a section of a chromosome is reversed.

question

deletion

answer

A change to a chromosome in which a fragment of the chromosome is removed.

question

translocation

answer

Change to a chromosome in which a fragment of one chromosome attaches to a nonhomologous chromosome.

question

Downs Syndrome

answer

A congenital disorder caused by having an extra Chromosome 21.

question

genomic imprinting

answer

Variation in phenotype depending on whether an allele is inherited from the male or female parent.

question

cytogenetic maps

answer

A chart of a chromosome that locates genes with respect to chromosomal features distinguishable in a microscope.

question

transformation

answer

A change in genotype and phenotype due to the assimilation of external DNA by a cell.

question

bacteriophages

answer

A virus that infects bacteria; also called a phage.

question

semiconservative model

answer

Type of DNA replication in which the replicated double helix consists of one old strand, derived from the old molecule, and one newly made strand.

question

origins of replication

answer

Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides.

question

replication fork

answer

A Y-shaped region on a replicating DNA molecule where new strands are growing.

question

DNA polymerase

answer

An enzyme that catalyzes the formation of the DNA molecule.

question

lagging strand

answer

A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5' to 3' direction away from the replication fork.

question

leading strand

answer

The new continuous complementary DNA strand synthesized along the template strand in the mandatory 5' to 3' direction.

question

Okazaki fragments

answer

Small fragments of DNA produced on the lagging strand during DNA replication, joined later by DNA ligase to form a complete strand.

question

primase

answer

An enzyme that joins RNA nucleotides to make the primer using the parental DNA strand as a template.

question

helicase

answer

An enzyme that untwists the double helix at the replication forks, separating the two parental strands and making them available as template strands.

question

single-strand binding protein (SSB)

answer

Binds to and stabilizes single-stranded DNA until it can be used as a template.

question

nuclease

answer

A DNA cutting enzyme that excises damaged DNA.

question

telomeres

answer

Repeated DNA sequences at the ends of eukaryotic chromosomes.

question

telomerase

answer

An enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells.

question

Watson and Crick

answer

Developed the double helix model of DNA.

question

Hersey-Chase Experiment

answer

Devised an experiment that showed that only the DNA of T2 phages enters a bacterial cell during infection.

question

Frederick Griffith

answer

Discovered transformation during an experiment that involved injecting mice with smooth S cells, rough R cells, heat-killed S cells, and heat-killed S cells with living R cells.

question

McCarty, Avery, & MacLeod

answer

Confirmed that the transforming agent in Griffith's experiment was DNA.

question

one gene-one polypeptide hypothesis

answer

The premise that a gene is a segment of DNA that codes for one polypeptide.

question

transcription

answer

Synthesis of an RNA molecule from a DNA template.

question

messenger RNA (mRNA)

answer

Carries genetic message from the DNA to he protein-synthesizing machinery of the cell.

question

Erwin Chargaff

answer

Discovered that DNA composition varies, but the amount of adenine is always the same as thymine and the amount of cytosine is always the same as guanine.

question

Meselson ; Stahl

answer

Determined that DNA replication is semiconservative.

question

translation

answer

The synthesis of a polypeptide, which occurs under the direction of mRNA.

question

ribosomes

answer

Complex particles that facilitate the orderly linking of amino acids into polypeptide chains.

question

RNA processing

answer

The modification of mRNA before it leaves the nucleus that is unique to eukaryotes.

question

primary transcript

answer

The initial mRNA transcript that is transcribed from a protein coding gene. Also called pre-mRNA.

question

triplet code

answer

Three-nucleotide long set that specifies a specific amino acid for a polypeptide chain.

question

template strand

answer

The DNA strand that provides the template for ordering the sequence of nucleotides in an mRNA transcript.

question

TATA box

answer

A promoter DNA sequence crucial in forming the transcription initiation complex.

question

promoter

answer

A specific nucleotide sequence in DNA that binds RNA polymerase and indicates where to start transcribing mRNA.

question

RNA polymerase

answer

Enzyme that links together the growing chain of ribonucleotides during transcription.

question

poly-A tail

answer

Modified end of the 3' end of an mRNA molecule consisting of the addition of some 50 to 250 adenine nucleotides.

question

terminator

answer

In prokaryotes, a special sequence of nucleotides in DNA that marks the end of a gene.

question

5' cap

answer

The 5' end of a pre-mRNA molecule modified by the addition of a cap of guanine nucleotide.

question

exons

answer

Coding segments of eukaryotic DNA.

question

anticodon

answer

Specialized base triplet at one end of a tRNA molecule that recognizes a particular complementary codon on an mRNA molecule.

question

one gene-one polypeptide hypothesis

answer

there is one gene that codes for one polypeptide

question

codons

answer

mRNA base triplets.

question

reading frame

answer

Reading mRNA nucleotides in the correct groupings.

question

transcription factors

answer

Collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription.

question

transcription initiation complex

answer

The assembly of transcription factors and RNA polymerase.

question

RNA splicing

answer

Process by which the introns are removed from RNA transcripts and the remaining exons are joined together.

question

introns

answer

Noncoding segments of nucleic acid that lie between coding sequences.

question

splicosome

answer

Different particles that recognize splice sites are compiled in a large assembly. A complex of RNA and protein subunits. Removes introns from a transcribed pre-RNA segments.

question

ribozymes

answer

RNA molecules that function as enzymes.

question

alternative RNA splicing

answer

Genes giving rise to two or more different polypeptides depending upon which segments are treated as exons.

question

domains

answer

Discrete structural and functional regions of proteins.

question

transfer RNA (tRNA)

answer

Interpreter of a series of codons along a mRNA molecule.

question

wobble

answer

Flexibility in the base-pairing rules in which the nucleotide at the 5' end of a tRNA anticodon can form hydrogen bonds with more than one kind of base in the third position of a codon.

question

ribosomal RNA (rRNA)

answer

RNA molecules that construct ribosomal subunits.

question

ribosomal P site

answer

Site that holds tRNA carrying the growing polypeptide chain.

question

ribosomal A site

answer

Site that holds the tRNA carrying the next amino acid to be added to the chain.

question

Ribosomal E site

answer

Site where discharged tRNAs leave the ribosome.

question

polyribosomes

answer

Strings of ribosomes that work together to translate a RNA message.

question

signal peptide

answer

A stretch of amino acids on a polypeptide that targets the protein to a specific destination in a eukaryotic cell.

question

signal-recognition particle

answer

A protein-RNA complex that recognizes a signal peptide as it emerges from the ribosome.

question

mutations

answer

Random errors in gene replication that lead to a change in the sequence of nucleotides. The source of all genetic diversity.

question

point mutations

answer

chemical changes in just one base pair of a gene

question

missense mutations

answer

Most common type of mutation, a base pair mutation in which the new codon makes sense in that it still codes for an amino acid.

question

nonsense mutations

answer

A mutation that changes an amino acid codon to one of three stop codons, resulting in a shorter and usually nonfunctional protein.

question

frameshift mutation

answer

Mutation occurring when the number of nucleotides inserted or deleted is not a multiple of three, resulting in improper grouping of nucleotides into codons.

question

mutagens

answer

physical and chemical agents that interact with DNA to cause mutations

question

activator

answer

A protein that binds to DNA and stimulates transcription of a specific gene.

question

bacteriophage

answer

A virus that infects bacteria; also called a phage.

question

capsid

answer

The protein shell that encloses a viral genome. It may be rod-shaped, polyhedral, or more complex in shape.

question

cyclic AMP (cAMP)

answer

A compound formed from ATP that acts as a second messenger.

question

episome

answer

A genetic element that can exist either as a plasmid or as part of the bacterial chromosome.

question

F factor

answer

A piece of DNA that confers the ability form a sex pili.

question

F plasmid

answer

The plasmid form of the F factor.

question

HIV (human immunodeficiency virus)

answer

The infectious agent that causes AIDS. HIV is a retrovirus.

question

host range

answer

The limited range of host cells that each type of virus can infect and parasitize.

question

inducer

answer

A specific small molecule that inactivates the repressor in an operon.

question

insertion sequence

answer

The simplest kind of transposable element, consisting of inverted repeats of DNA flanking a gene for transposase, the enzyme that catalyzes transposition.

question

lysogenic cycle

answer

A phage replication cycle in which the viral genome becomes incorporated into the bacterial host chromosome as a prophage and does not kill the host.

question

lytic cycle

answer

A type of viral (phage) replication cycle resulting in the release of new phages by lysis (and death) of the host cell.

question

nucleoid

answer

A dense region of DNA in a prokaryotic cell.

question

operator

answer

Region of DNA that controls RNA polymerase's access to a set of genes with related functions.

question

operon

answer

A unit of genetic function common in bacteria and phages, consisting of coordinately regulated clusters of genes with related functions.

question

plasmid

answer

A small ring of DNA that carries accessory genes separate from those of a bacterial chromosome; also found in some eukaryotes, such as yeast.

question

prophage

answer

A phage genome that has been inserted into a specific site on the bacterial chromosome.

question

provirus

answer

Viral DNA that inserts into a host genome.

question

R plasmid

answer

A bacterial plasmid carrying genes that confer resistance to certain antibiotics.

question

regulatory gene

answer

A gene that codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes.

question

repressor

answer

A protein that suppresses the transcription of a gene.

question

retrovirus

answer

An RNA virus that reproduces by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome; an important class of cancer-causing viruses.

question

reverse transcriptase

answer

An enzyme encoded by some certain viruses (retroviruses) that uses RNA as a template for DNA synthesis.

question

temperate phage

answer

A phage that is capable of reproducing by either the lytic or lysogenic cycle.

question

transposable genetic element

answer

A segment of DNA that can move within the genome of a cell by means of a DNA or RNA intermediate; also called a transposable element.

question

transposon

answer

A transposable genetic element that moves within a genome by means of a DNA intermediate.

question

vaccine

answer

A harmless variant or derivative of a pathogen that stimulates a host's immune system to mount defenses against the pathogen.

question

viral envelope

answer

A membrane that cloaks the capsid that in turn encloses a viral genome.

question

cell differentiation

answer

the process by which a cell becomes specialized for a specific structure or function.

question

gene expression

answer

Conversion of the information encoded in a gene first into messenger RNA and then to a protein.

question

differential gene expression

answer

The expression of different sets of genes by cells with the same genome.

question

histone acetylation

answer

The attachment of acetyl groups to certain amino acids of histone proteins.

question

DNA methylation

answer

The addition of methyl groups to bases of DNA after DNA synthesis; may serve as a long-term control of gene expression.

question

epigenetic inheritance

answer

Inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence.

question

control elements

answer

segments of noncoding DNA in eukaryotic genes that help regulate transcription by binding to certain proteins.

question

enhancer

answer

A DNA segment containing multiple control elements that can recognize certain transcription factors that stimulate the transcription of nearby genes.

question

micro-RNA (miRNA)

answer

small single stranded RNA molecules that bind to mRNA and can degrade mRNA or block its translation.

question

siRNAs (small interfering RNAs)

answer

RNAs of similar size and functions as miRNAs that inhibit gene expression.

question

proteasomes

answer

A giant protein complex that recognizes and destroys proteins tagged for elimination by the small protein ubiquitin.

question

RNA interference

answer

Blocking gene expression by means of an miRNA silencing complex.

question

recombinant DNA

answer

A DNA molecule made in vitro with segments from different sources.

question

biotechnology

answer

The manipulation of living organisms or their components to produce useful products.

question

gene cloning

answer

The production of multiple copies of a gene.

question

restriction enzyme

answer

A degradative enzyme that recognizes and cuts up DNA (including that of certain phages) that is foreign to a bacterium.

question

restriction site

answer

A specific sequence on a DNA strand that is recognized as a cut siteby a restriction enzyme.

question

restriction fragment

answer

The fragment of DNA that is produced by cleaving DNA with a restriction enzyme.

question

sticky end

answer

A single-stranded end of a double-stranded DNA restriction fragment.

question

DNA ligase

answer

A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA fragment to the 5' end of a growing chain.

question

cloning vector

answer

DNA molecules that can carry foreign DNA into a host cell and replicate there.

question

nucleic acid hybridization

answer

Base pairing between a gene and a complementary sequence on another nucleic acid molecule.

question

nucleic acid probe

answer

Radioactively labeled nucleic acid molecule used to tag a particular DNA sequence.

question

denaturation

answer

In proteins, a process in which a protein unravels and loses its native conformation, thereby becoming biologically inactive. In DNA, the separation of the two strands of the double helix.

question

genomic library

answer

A set of thousands of DNA segments from a genome, each carried by a plasmid, phage, or other cloning vector.

question

complementary DNA (cDNA)

answer

DNA molecule made in vitro using mRNA as a template and the enzyme reverse transcriptase.

question

cDNA library

answer

A limited gene library using complementary DNA. The library includes only the genes that were transcribed in the cells examined.

question

expression vector

answer

A cloning vector that contains the requisite prokaryotic promoter just upstream of a restriction site where a eukaryotic gene can be inserted.

question

yeast artificial chromosome (YAC)

answer

A cloning vector that has telomeres and a centromere that can accommodate large DNA inserts and uses the eukaryote yeast as a host cell.

question

electroporation

answer

A technique to introduce recombinant DNA into cells by applying a brief electrical pulse to a solution containing the cells. The pulse creates temporary holes in the cells' plasma membrane, through which DNA can enter.

question

polymerase chain reaction (PCR)

answer

A technique for amplifying DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides.

question

gel electrophoresis

answer

The separation of nucleic acids or proteins, on the basis of their size and electrical charge, by measuring their rate of movement through an electrical field in a gel.

question

Southern blotting

answer

A hybridization technique that enables researchers to determine the presence of certain nucleotide sequences in a sample of DNA.

question

restriction fragment length polymorphisms (RFLPs)

answer

differences in the restriction sites on homologous chromosomes that result in different restriction fragment patterns.

question

Human Genome Project

answer

An international collaborative effort to map and sequence the DNA of the entire human genome.

question

linkage map

answer

A genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes.

question

physical map

answer

A genetic map in which the actual physical distances between genes or other genetic markers are expressed, usually as the number of base pairs along the DNA.

question

bacterial artificial chromosome (BAC)

answer

An artificial version of a bacterial chromosome that can carry inserts of 100, 000 to 500, 000 base pairs.

question

DNA sequencing

answer

Determining the exact order of the base pairs in a segment of DNA.

question

genetic engineering

answer

The direct manipulation of genes for practical purposes.

question

genomic equivalence

answer

All cells in an organism contain the same complement of genes. These are the same set of genes that are established in the fertilized egg.

question

totipotent

answer

Cells that are able to develop into any type of cell found in the body.

question

cloning

answer

Making a genetically identical copy of DNA or of an organism.

question

nuclear transplantation

answer

A technique in which the nucleus of one cell is placed into another cell that already has a nucleus or in which the nucleus has been previously destroyed.

question

reproductive cloning

answer

Using a somatic cell from a multicellular organism to make one or more genetically identical individuals.

question

stem cell

answer

Unspecialized cell that can both reproduce itself indefinitely and differentiate into specialized cells of one or more types.

question

pluripotent

answer

Able to give rise to multiple, but not all, cell types.

question

therapeutic cloning

answer

The cloning of human cells by nuclear transplantation for therapeutic purposes, such as the generation of embryonic stem cells to treat disease.

question

determination

answer

The point during development at which a cell becomes committed to a particular fate due to cytoplasmic effects or to induction by neighboring cells.

question

cytoplasmic determinants

answer

Maternal substances in egg that influence the course of early development.

question

induction

answer

The process by which neighboring cells can influence the determination of a cell.

question

photoautotrophs

answer

Organisms that use light as a source of energy to synthesize organic substances.

question

leaf

answer

The major sites of photosynthesis in most plants.

question

chlorophyll

answer

Green pigment located within the chloroplasts.

question

mesophyll

answer

Spongy tissue in the interior of the leaf where most chloroplasts are found.

question

stomata

answer

Microscopic pores in the leaf which lets CO2 in and O2 out. Also where water is lost.

question

veins

answer

Bundles of xylem and phloem.

question

granum

answer

Stack of thylakoids.

question

stroma

answer

Fluid inside the chloroplast where the Calvin Cycle happens.

question

thylakoid

answer

Flattened membranes in the chloroplast where the light reactions take place.

question

light reaction

answer

Part of photosynthesis that involves light. ATP and NADPH are produced. Takes place on the thylakoid membrane.

question

pigments

answer

Molecules that absorb, reflect, or transmit light.

question

photosystem

answer

A cluster of pigments embedded into a thylakoid membrane.

question

oxidizing agent

answer

Accepts electrons and becomes reduced.

question

reducing agent

answer

Donates electrons and becomes oxidized.

question

noncyclic photophosphorolation

answer

Photosystem II performs photolysis to provide electrons for the electron transport chain that drives a chemiosmotic gradient that produces ATP.

question

cyclic photophosphorolation

answer

Only Photosystem I works. ATP is made, no oxygen is produced, no water is split, no NADPH is made.

question

photolysis

answer

In the thylakoid membranes of a chloroplast during light-dependant reactions, two molecules of water are split to form oxygen, hydrogen ions, and electrons.

question

phosphoralation

answer

Process of adding a phosphate group.

question

carbon fixation

answer

The initial incorporation of carbon into organic compounds.

question

calvin cycle

answer

Carbon fixation process in photosynthesis. Forms sugar and other organic compounds.

question

absorption spectrum

answer

A graph plotting a pigment light light absorption.

question

action spectrum

answer

A profile of the relative performance of the different wavelengths in photosynthesis.

question

chlorophyll a

answer

Only pigment that can participate directly in the light reactions.

question

carotenoids

answer

Accessory pigments that broaden the spectrum of colors that can drive photosynthesis.

question

p680

answer

Reaction center chlorophyll in the photosystem II.

question

p700

answer

Reaction center cholophyll in the photosystem I.

question

reaction center

answer

The location of the first light driven chemical reaction of photosynthesis.

question

primary electron acceptor

answer

Specialized molecule that shares a reaction center with the chlorophyll a molecule in the light reaction. traps high energy electron before it can return to ground state in the chlorophyll.

question

chemiosmosis

answer

Process by which a Hydrogen pump pumps protons into the thylakoid membrane. H+ passively flows through the ATP synthase which leads to the creation of ATP.

question

rubisco

answer

The most abundant protein on earth. Performs Carbon Fixation in the Calvin Cycle.

question

sepal

answer

A modified leaf in angiosperms that helps enclose and protect a flower bud before it opens.

question

petal

answer

A modified leaf of a flowering plant; petals are the often colorful parts of a flower that advertise it to insects and other pollinators.

question

stamen

answer

The pollen-producing reproductive organ of a flower, consisting of an anther and a filament.

question

carpel

answer

The ovule-producing reproductive organ of a flower, consisting of the stigma, style, and ovary.

question

receptacle

answer

The base of a flower; the part of the stem that is the site of attachment of the floral organs.

question

anther

answer

In an angiosperm, the terminal pollen sac of a stamen, where pollen grains containing sperm-producing male gametophytes form.

question

ovary

answer

In flowers, the portion of a carpel in which the egg-containing ovules develop.

question

style

answer

The stalk of a flower's carpel, with the ovary at the base and the stigma at the top.

question

stigma

answer

The sticky part of a flower's carpel, which receives pollen grain.

question

ovule

answer

A structure that develops within the ovary of a seed plant and contains the female gametophyte.

question

pistil

answer

A single carpel or a group of fused carpels in a flower.

question

complete flower

answer

A flower that has all four basic floral organs: sepals, petals, stamens, and carpels.

question

incomplete flower

answer

A flower in which one or more of the four basic floral organs such as sepals, petals, stamens, or carpels are either absent or nonfunctional.

question

inflorescence

answer

A group of flowers tightly clustered together.

question

monoecious

answer

If staminate and carpellate flowers are on the same plant.

question

dioecious

answer

If staminate and carpellate flowers are on different plants.

question

self-incompatibility

answer

The ability of a seed plant to reject its own pollen and sometimes the pollen of closely related individuals.

question

endosperm

answer

In angiosperms, a nutrient-rich tissue formed by the union of a sperm with two polar nuclei during double fertilization. Provides nourishment to the developing embryo in angiosperm seeds.

question

double fertilization

answer

A mechanism of fertilization in angiosperms, in which two sperm cells unite with two cells in the embryo sac to form the zygote and endosperm.

question

pollen tube

answer

A tube that forms after germination of the pollen grain and that functions in the delivery of sperm to the ovule.

question

seed coat

answer

A tough outer covering of a seed, formed from the outer coat of an ovule.

question

hypocotyl

answer

The part of a plant embryo directly below the cotyledons, forming a connection with the radicle.

question

radicle

answer

An embryonic root of a plant.

question

coleoptile

answer

Covers and protects the shoot as it grows upward.

question

fruit

answer

A mature ovary of a flower that protects dormant seeds and often aids in their dispersal.

question

simple fruit

answer

A fruit derived from a single carpel or several fused carpels.

question

aggregate fruit

answer

A fruit derived from a single flower that has more than one carpel.

question

multiple fruit

answer

A fruit derived from an entire inflorescence.

question

dormancy

answer

A condition typified by extremely low metabolic rate and a suspension of growth and development.

question

etiolation

answer

Plant morphological adaptations for growing in darkness.

question

de-etiolation

answer

The changes a plant shoot undergoes in response to sunlight; also known informally as greening.

question

tropism

answer

A growth response that results in the curvature of whole plant organs toward or away from stimuli owing to differential rates of cell elongation.

question

phototropism

answer

Growth of a plant shoot toward or away from light.

question

auxin

answer

Indoleacetic acid (IAA), a natural plant hormone that has a variety of effects, including cell elongation, root formation, secondary growth, and fruit growth.

question

cytokinins

answer

A class of plant hormones that retard aging and act in concert with auxin to stimulate cell division, influence the pathway of differentiation, and control apical dominance.

question

gibberellins

answer

A class of related plant hormones that stimulate growth in the stem and leaves, trigger the germination of seeds and breaking of bud dormancy, and stimulate fruit development.

question

abscisic acid (ABA)

answer

A plant hormone that slows down growth, promotes seed dormancy and facilitates drought tolerance.

question

ethylene

answer

The only gaseous plant hormone. Among its many effects are response to mechanical stress, programmed cell death, leaf abscission, and fruit ripening.

question

triple response

answer

A plant growth maneuver in response to mechanical stress, involving slowing of stem elongation, a thickening of the stem, and a curvature that causes the stem to start growing horizontally.

question

apoptosis

answer

Programmed cell death.

question

leaf abscission

answer

Aging and dropping of leaves controlled by auxin and ethylene.

question

fruit ripening

answer

A burst of ethylene production in a fruit triggers the ripening process.

question

photomorphogenesis

answer

Effects of light on plant morphology.

question

blue-light photoreceptors

answer

A class of light receptors in plants. Blue light initiates a variety of responses, such as phototropism and slowing of hypocotyl elongation.

question

phytochromes

answer

A class of light receptors in plants. Mostly absorbing red light, these photoreceptors regulate many plant responses, including seed germination and shade avoidance.

question

circadian rhythm

answer

A physiological cycle of about 24 hours that is present in all eukaryotic organisms and that persists even in the absence of external cues.

question

photoperiodism

answer

A physiological response to photoperiod, the relative lengths of night and day. An example of photoperiodism is flowering.

question

short-day plant

answer

A plant that flowers only when the light period is shorter than a critical length. Usually fall or winter.

question

long-day plant

answer

A plant that flowers only when the light period is longer than a critical length. Usually spring or early summer.

question

day-neutral plant

answer

A plant whose flowering is not affected by photoperiod.

question

vernalization

answer

The use of cold treatment to induce a plant to flower.

question

florigen

answer

A flowering signal, not yet chemically identified, that may be a hormone or may be a change in relative concentrations of multiple hormones.

question

jasmonic acid

answer

An important molecule in plant defense against herbivores.

question

virulent

answer

A term describing a pathogen against which a plant has little specific defense.

question

avirulent

answer

A term describing a pathogen that can only mildly harm, but not kill, the host plant.

question

gene-for-gene recognition

answer

A widespread form of plant disease resistance involving recognition of pathogen-derived molecules by the protein products of specific plant disease resistance genes.

question

elicitors

answer

A molecule that induces a broad type of host defense response

question

oligosaccharins

answer

A type of elicitor that is derived from cellulose fragments released by cell wall damage

question

PR protein

answer

A protein involved in plant responses to pathogens (PR = pathogenesis-related).

question

hypersensitive response (HR)

answer

A plant's localized defense response to a pathogen

question

systemic acquired resistance (SAR)

answer

A defensive response in infected plants that helps protect healthy tissue from pathogenic invasion.

question

salicylic acid

answer

A plant hormone that may be partially responsible for activating systemic acquired resistance to pathogens.

question

reception

answer

The target cell's detection of a signal molecule coming from outside the cell.

question

transduction

answer

The binding of the signal molecule changes the receptor protein in some way.

question

response

answer

The transduced signal finally triggers a specific cellular response.

question

G-protein-linked receptor

answer

A plasma membrane receptor that works with the help of a G-protein.

question

receptor tyrosine kinase

answer

A receptor with enzymatic activity that can trigger more than one signal transduction pathway at once, helping the cell regulate and coordinate many aspects of cell growth and reproduction.

question

ligand-gated ion channel

answer

Type of membrane receptor that has a region that can act as a "gate" when the receptor changes shape.

question

diacylglycerol (DAG)

answer

A second messenger produced by the cleavage of a certain kind of phospholipid in the plasma membrane.

question

topoisomerase

answer

Enzyme that functions in DNA replication, helping to relieve strain in the double helix ahead of the replication fork.

question

chromatin

answer

The complex of DNA and proteins that makes up a eukaryotic chromosome.

question

totipotent

answer

Stem cells with the potential to differentiate into any type of cell.

question

repolarization

answer

Return of the cell to resting state, caused by reentry of potassium into the cell while sodium exits the cell.

question

virulent

answer

Viruses that reproduce only by the lytic cycle.

Ultimate AP Biology Vocabulary Review – Flashcards

Unlock all answers in this set

Haven't found what you were looking for?

Search for samples, answers to your questions and flashcards