question

Genetics

answer

the field of biology devoted to understanding how characteristics are transmitted from parents to offspring

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Heredity

answer

the transmission of characteristics from parents to offspring

question

Trait

answer

a genetically determined variant of a characteristic

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Pollination

answer

a process that occurs when pollen grains produced in the male reproductive parts of a flower, called the anthers, are transferred to the female reproductive part of a flower, called the stigma

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Self-Pollination

answer

a process that occurs when pollen is transferred from the anthers of a flower to the stigma of either that flower or another flower on the same plant

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Cross-Pollination

answer

a process that occurs between flowers of two plants

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True-Breeding

answer

plants that are pure for a trait that always produce offspring with that trait when they self-pollinate

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P Generation

answer

the true-breeding parents

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F1 Generation

answer

the first filial generation; offspring of the P generation

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F2 Generation

answer

the second filial genration

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Dominant

answer

a factor that masked, or dominated, the factor for the other trait in the pair

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Recessive

answer

the factor that controlled the trait that did not apear in the F1 generation but reappeared in the F2 generation

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Law of Segregation

answer

states that a pair of factors is segregated, or separated, during the formation of gametes

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Law of Independent Assortment

answer

states that factors separated independently of one another during the formation of gametes

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Molecular Genetics

answer

the study of the structure and function of chromosomes and genes

question

Allele

answer

Each of two or more alternative forms of a gene

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Genotype

answer

an organism's genetic makeup

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Phenotype

answer

an organism's appearance

question

Homozygous

answer

the organism is said to be this when both alleles of a pair are alike

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Heterozygous

answer

the organism is said to be this when both alleles of a pair are different

question

Probability

answer

the likelihood that a specific event will occur

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Monohybrid Cross

answer

a cross in which only one characteristic is tracked

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Punnett Square

answer

a diagram scientists use to aid them in predicting the probable distribution of inherited traits in the offspring

question

Genotypic Ratio

answer

the ratio of the genotypes that appear in offspring

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Phenotypic Ratio

answer

the ratio of the offspring's phenotypes

question

Testcross

answer

a cross in which an individual of unknown genotype is crossed with a homozygous recessive individual

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Complete Dominance

answer

a relationship in which one allele is completely dominant over another

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Incomplete Dominance

answer

a relationship in which the F1 offspring will have a phenotype in between that of the parents

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Codominance

answer

a relationship that occurs when both alleles for a gene are expressed in a heterozygous offspring

question

Dihybrid Cross

answer

a cross in which two characteristics are tracked

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Chromosomes

answer

Rod-shaped structures made of DNA and proteins.

question

Histones

answer

Maintain the shape of chromosomes and aid in the tight packing of DNA.

question

chromatid

answer

Each half of the chromosomes.

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Centromere

answer

The point where two Chromatids are attached.

question

Chromatin

answer

Less tightly coiled DNA-protein complex.

question

Sex Chromosomes

answer

Determine the sex of the organism.

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Autosomes

answer

All the other chromosomes in the organism.

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Homologous Chromosomes

answer

Two copies of each Autosomes.

question

Karyotype

answer

A photomicrograph of the chromosomes in a normal dividing cell found in a human.

question

Diploid

answer

Two sets of chromosomes. Body Cells.

question

Haploid

answer

Sperm Cells and Egg Cells.

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Binary Fission

answer

The division of a prokaryotic cell into two offspring cells.

question

Mitosis

answer

Cell division that results in new cells.

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Asexual Reproduction

answer

Is the production of offspring from one parent.

question

Meiosis

answer

Reduces the chromosome count by half in new cells.

question

Gametes

answer

Haploid reproiductive cells.

question

Interphase

answer

The time between cell division. (The Phase)

question

Cytokinesis

answer

The division of the cells cytoplasm.

question

Prophase

answer

The first phase of Mitosis.

question

Spindle Fiber

answer

Radiate from the newly seperated centromeres to prepare for Metaphase.

question

Metaphase

answer

The second phase of Mitosis, chromosomes are larger in this phase.

question

Anaphase

answer

The third phase, chromatids of each chromosome seperate at the centromere and slowly move away from eachother.

question

Telophase

answer

After the chromosome seperates, the cell seals off, Final Phase of Mitosis.

question

Cell Plate

answer

In a plant cell, midline of dividing cells. Becomes the cell wall eventually.

question

Synapsis

answer

The pairing of Homologous Chromosomes.

question

Tetrad

answer

Each pair of Homologous Chromosomes.

question

Crossing-over

answer

Chromotids may break off and connect to adjacent Homologous Chromosomes.

question

Genetic Recombination

answer

A new mixture of genetic material is created.

question

Independant Assortment

answer

The random seperation of the Homologous Chromosomes.

question

Spermatogensis

answer

The production of sperm cells.

question

Oogenesis

answer

The production of mature egg cells.

question

Polar Body

answer

The other three products of meiosis that eventually degenerate.

question

Sexual Reproduction

answer

The production of offspring through meiosis and the union of a sperm and an egg cell.

question

sex chromosome

answer

one of the pair of chromosomes that determine the sex of an individual

question

autosome

answer

any chromosome that is not a sex chromosome

question

sex-linked trait

answer

a trait that is determined by a gene found on one of the sex chromosomes, such as the X chromosome or the Y chromosome in humans

question

linked gene

answer

one of a pair of genes that tend to be inherited together

question

chromosome map

answer

a diagram of gene positions on a chromosome

question

map unit

answer

in chromosome mapping, an increment of 1 percent in the frequency of crossing-over

question

germ-cell mutation

answer

mutation that occurs in an organism's gametes

question

somatic-cell mutation

answer

a mutation that occurs in a body cell

question

lethal mutation

answer

a gene or chromosomal mutation that influences the development of an organism in such a way that the organism cannot survive

question

deletion

answer

the loss of a part of DNA from a chromosome

question

inversion

answer

a reversal in the order of the genes, or of a chromosome segment, within a chromosome

question

translocation

answer

the movement of a segment of DNA from one chromosome to another, which results in a change in the position of the segment; also the movement of soluble nutrients from one part of a plant to another

question

nondisjunction

answer

the failure of homologous chromosomes to separate during meiosis I or the failure of sister chromatids to separate during mitosis or meiosis II

question

point mutation

answer

a mutation in which only one nucleotide or nitrogenous base in a gene is changed

question

substitution

answer

a mutation in which one nucleotide is replaced by another nucleotide

question

frameshift mutation

answer

a mutation, such as the insertion or deletion of a nucleotide in a coding sequence, that results in the misreading of the code during translation because of a change in the reading frame

question

insertion mutation

answer

a mutation in which one or more nucleotides are added to a gene

question

pedigree

answer

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

question

carrier

answer

in biology, an individual who has one copy of a recessive autosomal allele that causes disease in the homozygous condition

question

genetic disorder

answer

an inherited disease or disorder that is caused by a mutation in a gene or by a chromosomal defect

question

polygenic

answer

describes a characteristic that is influenced by many genes

question

complex character

answer

a character such as skin color that is influenced strongly by both genes and the environment

question

multiple alleles

answer

more than two alleles (versions of the gene) for a genetic trait

question

codominance

answer

a condition in which both alleles for a gene are fully expressed

question

incomplete dominance

answer

a condition in which a trait in an individual is intermediate between the phenotype of the individual's two parents because the dominant allele is unable to express itself fully

question

sex-influenced genes

answer

an autosomal trait that is influenced by the presence of male or female sex hormones

question

Huntington's disease

answer

an autosomal dominant condition characterized by forgetfulness and irritability

question

amniocentesis

answer

a procedure used in fetal diagnosis in which amniotic fluid is removed from the uterus of the pregnant woman

question

chorionic villi sampling

answer

a procedure in which the chorionic villi to are analyzed to diagnose fetal genotypes

question

genetic counseling

answer

the process of testing and informing potential parents about their genetic makeup and the likelihood that they will have offspring with genetic defects or hereditary diseases

question

gene therapy

answer

a technique that places a gene into a cell to correct a hereditary disease or to improve the genome

question

virulent

answer

describes a microorganism that causes disease and that is highly infectious; strictly, refers only to viruses that reproduce from the lytic cycle

question

transformation

answer

the transfer of genetic material in the form of DNA fragments from one cell to another or from one organism to another

question

bacteriophage

answer

a virus that infects bacteria

question

nucleotide

answer

in a nucleic-acid chain, a subunit that consists of a sugar, a phosphate, and a nitrogenous base

question

deoxyribose

answer

a five-carbon sugar that is a component of DNA molecules

question

nitrogenous base

answer

an organic base that contains nitrogen, such as a purine or pyrimidline; a subunit of a nucleotide in DNA and RNA

question

purine

answer

a nitrogenous base that has a double-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA; either adenine or guanine

question

pyrimidine

answer

a nitrogenous base that has a single-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA; thymine, cytosine, or uracil

question

base pairing rules

answer

the rules stating that cytosine pairs with guanine and adenine pairs with thymine in DNA, and adenine pairs with uracil in RNA

question

complementary base pair

answer

the nucleotide bases in one strand of DNA or RNA that are paired with those of another strand

question

base sequence

answer

the order of the nitrogenous bases on a chain of DNA

question

DNA replication

answer

the process of makinf a copy of DNA

question

helicase

answer

an enzyme that separates DNA strands

question

replication fork

answer

a Y-shaped point that results when the two strandes of a DNA double helix separate so that the DNA molecule can be replicated

question

DNA polymerase

answer

an enzyme that catalyzes the formation of the DNA molecule

question

semi-conservatice replication

answer

in each new DNA double helix, one strand is from the original molecule,and one strand is new

question

mutation

answer

a change in the nucleotide-base sequence of a gene or DNA molecule

question

RNA

answer

a natrual polymer that is present in all living cells and that plays a role in protein synthesis

question

transcription

answer

the process of forming a nucleic acid by using another molecule as a template; particulary the process of synthesizing RNA by using one strand of a DNA molecule as a template

question

translation

answer

the portion of protein synthesis that takes place at ribosomes and that uses the codons on mRNA molecules to specify the sequence of amino acids in polypeptide chains

question

protein synthesis

answer

the formation of proteins by using information contained in DNA and carried by mRNA

question

ribose

answer

a five-carbon sugar present in RNA

question

mRNA (messenger RNA)

answer

a single-stranded RNA molecule that encodes the information to make a protein

question

tRNA (transfer RNA)

answer

an RNA molecule that transfers amino acids to the growing end of a polypeptide chain during translation

question

RNA polymerase

answer

an enzyme that starts (catalyzes) the formation of RNA by using a strand of a DNA molecule as a template

question

promoter

answer

a nucleotide sequence on a DNA molecule to which an RNA polymerase molecule binds, which initiates the transcription of a specific gene

question

termination signal

answer

a specific sequence of nucleotides that marks the end of a gene

question

genetic code

answer

the rule that describes how a sequence of nucleotides, read in groups of three consecutive nucleotides (triplets) that correspond to specific amino acids, specifies the amino acid sequence of a protein

question

codon

answer

in DNA, a three-nucleotide sequence that encodes an amino acid or signifies a start signal or a stop signal

question

anticodon

answer

a region of tRNA that consistsof three bases complementary to the codon of mRNA

question

genome

answer

the complete genetic material contained in an individual

question

rRNA (ribosomal RNA)

answer

an organelle that contains most of the RNA in the cell and that is responsible for ribosome function

question

biogenesis

answer

the theory that living organisms come only from other living organisms

question

spontaneous generation

answer

an early and now disproved theory that living organisms come to life spontaneously from nonliving material

question

radiometric dating

answer

a method of determining the absolute age of an object by comparing the relative percentages of a radioactive (parent) isotope and a stable (daughter) isotope

question

isotope

answer

an atom that has the same number of protons (or the same atomic number) as other atoms of the same element do but that has a different number of neutrons (and thus a different atomic mass)

question

mass number

answer

the sum of the numbers of protons and neutrons in the nucleus of an atom

question

radioactive decay

answer

the disintegration of an unstable atomic nucleus into one or more different nuclides, accompanied by the emission of radiation, the nuclear capture or ejection of electrons, or fission

question

radioactive isotope

answer

an isotope that has an unstable nucleus and that emits radiation

question

half-life

answer

the time required for half of a sample of a radioactive isotope to break down by radioactive decay to form a daughter isotope

question

microsphere

answer

a microscopic spherical structure composed of many protein molecules that are organized as a membrane

question

coacervate

answer

a mass of colloidal substances held together by electrostatic attraction

question

ribozyme

answer

a type of RNA that can act as an enzyme

question

archaea

answer

prokaryotes (most of which are known to live in extreme environments) that are distinguished from other prokaryotes by differences in their genetics and in the makeup of their cell wall;

question

chemosynthesis

answer

the production of carbohydrates through the use of energy from inorganic molecules instead of light

question

ozone

answer

a gas molecule that is made up of three oxygen atoms

question

endosymbiosis

answer

a mutually beneficial relationship in which one organism lives within another

question

cyanobacteria

answer

a group of photosynthetic, unicellular prokaryotes

question

absolute age

answer

the actual age in years of a fossil

question

acquired trait

answer

a trait not determined by genes but arising as a result of experience or behavior

question

adapt

answer

in populations, to change genetically over generations to become more suited to the environment

question

adaptation

answer

an inherited trait that increases an organism's chance of survival in a particular environment

question

adaptive advantage

answer

a favorable trait in an organism

question

adaptive radiation

answer

an evolutionary pattern in which many species evolve from a single ancestral species

question

analogous structure

answer

in evolution, structures in more than one organism that have similar appearance and function but different embryological origins

question

artificial selection

answer

breeding of organisms by humans for specific phenotypic characteristics

question

biogeography

answer

study of the geographical distribution of fossils and living organisms

question

cast

answer

a type of fossil formed when sediments fill in the cavity left by a decomposing organism

question

coevolution

answer

the mutual evolution of two different species interacting with each other

question

conserve

answer

the act of preserving genes that remain unchanged in DNA

question

convergent evolution

answer

the process by which unrelated species become more similar as they adapt to the same kind of environment

question

divergent evolution

answer

the process of two or more related species becoming more and more dissimilar

question

extinction

answer

the dying out of a species

question

fitness

answer

a measurement of the ability of a species to respond to the pressures of natural selection; the ability of individuals to survive to propagate their genes

question

fossil

answer

the remains or traces of a once-living organism

question

homologous

answer

features similar features that originated in a shared ancestor

question

law of superposition

answer

a law that states that successive layers of rock or soil were deposited on top of one another and the lowest level is oldest

question

mass extinction

answer

one of the brief periods of time during which large numbers of species disappeared

question

mold

answer

a type of fossil formed from an impression of the shape or tracks of an organism; in fungi, a mass of tangled filaments of cells, such as the fungus that grows on bread

question

natural selection

answer

the process by which organisms with favorable variations reproduce at higher rates than those without such variations

question

population

answer

all the members of a species that live in the same area and make up a breeding group

question

relative age

answer

the comparative ages of fossils found within a single stratum

question

sediment

answer

dust, sand, or mud deposited over time by wind or water

question

stratum

answer

in geology, a layer of soil or rock in a cross section of the Earth

question

uniformitarianism

answer

a principle that states that the geological structure of Earth resulted from cycles of observable processes and that these processes operate continuously

question

vestigial

answer

referring to a functionless structure that was functional in an ancestral species

question

biodiversity

answer

the variety of organisms considered at all levels from populations to ecosystems

question

taxonomy

answer

the science of describing, naming, and classifying organisms

question

taxon

answer

any particular group within a taxonomic system

question

kingdom

answer

in a traditional taxonomic system, the highest taxonomic category, which contains a group of similar phyla

question

domains

answer

categories above the kingdom level

question

phyla (singular,phylum)

answer

Subsets below the kingdom level.

question

classes

answer

category contained within a phylum or division and containing orders

question

orders

answer

the category contained within a class and containing families.

question

family

answer

In a traditional taxonomic system, the category contained within an order and containing genera.

question

genus

answer

In a traditional taxonomic system, the category contained within a family and containing species

question

species

answer

the smallest grouping, which contains only a single kind of organism

question

binomial momenclature

answer

system of two-part names

question

subspecies

answer

variations of a species that live in different geographic areas

question

systematics

answer

the classification of living organisms in terms of their natural relationships; it includes describing, naming, and classifying the organisms

question

phylogenetics

answer

the analysis of evolutionary, or ancestral, relationships between taxa

question

phylogenetic diagram

answer

a branching diagram that models the relationships by ancestry between different species or other taxonomic groups

question

cladistics

answer

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

question

shared character

answer

A feature that is shared by all members of a particular group of organisms

question

derived character

answer

A feature that evolved only within a particular taxonomic group

question

clade

answer

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

question

cladograms

answer

A diagram that is based on patterns of shared, derived traits and that shows the evolutionary relationships between groups of organisms.

question

bacteria

answer

in a modern taxonomic system, a domain made up of prokaryotes that usually have a cell wall and that usually reproduce by cell division; this domain aligns with the traditional kingdom Eubacteria

question

archaea

answer

in a modern taxonomic system, a domain made up of prokaryotes that can live in extreme environments and that are differentiated from other prokaryotes by various important chemical differences; this domain aligns with the traditional kingdom Archaebacteria.

question

eukarya

answer

domain which consists of eukaryotic organisms. Cells of organisms ar large and have a true nucleus and complex cellular organelles. Domain eukarya includes plants, animals, fungi

question

eubactria (true bacteria)

answer

aligns with domain Bacteria. Names means true bacteria

question

archaebacteria (ancient bacteria)

answer

aligns with domain Archaea. Name means ancient bacteria

question

protista

answer

Kingdom composed of eukaryotes that are not classified as plants, animals, or fungi

question

fungi

answer

a classification kingdom made up of nongreen, eukaryotic organisms that get food by breaking down organic matter and absorbing the nutrients, reproduce by means of spores, and have no means of movement

question

plantae

answer

a classification kingdom made up of eukaryotic, multicellular organisms that have cell walls made mostly of cellulose, that have pigments that absorb light, and that supply energy and oxygen to themselves and to other life-forms through photosynthesis

question

animalia

answer

the classification kingdom containing complex, multicellular organisms that lack cell walls, are usually able to move around, and possess specialized sense organs that help them quickly respond to their environment

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