Honors Biology Midterm Review Guide

biology
the science that seeks to understand the living world
cell
a collection of living matter enclosed by a barrier that separates the cell from its surroundings
sexual reproduction
cells from two different parents unite to produce the first cell of a new organism
asexual reproduction
the new organism has a single parent
metabolism
combination of chemical reactions through which an organism builds up or breaks down materials as it carries out its life process
stimulus
a signal to which an organism responds
homeostasis
process by which organisms keep internal conditions (temperature and water content) fairly constant to survive
evolution
change in a kind of organism over time
Describe some characteristics of living things
organized, adapt, evolve, adjust to surroundings, made up of units called cells, reproduce, based on a universal genetic code, grow and develop, obtain and use materials and energy, respond to their environment, change over time
Explain how life can be studied at different levels
life can be studied form molecules- cells- group of cells (tissue, organs, organ systems)- organisms- population- community- ecosystem- biosphere
monomer
smaller units that join together to form polymers
polymer
large compound formed from combinations of many monomers
carbohydrate
compound made up of carbon, hydrogen, and oxygen atoms; major source of energy for the human body
monosaccharide
single sugar molecules
polysaccharide
large macromolecules formed from monosaccharides
lipid
monosaccharides made mostly from carbon and hydrogen atoms; including fats, oils, and waxes
nucleic acid
macromolecules containing hydrogen, oxygen, nitrogen, cardon, and phosphorus
nucleotide
monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base
ribonucleic acid (RNA)
one kind of nucleic acids containing sugar ribose
deoxyribonucleic acid (DNA)
one kind of nucleic acids containing sugar deoxyribose
protein
macromolecule that contains carbon, hydrogen, oxygen, and nitrogen
amino acid
compounds with an amino group (-NH2) on one end and a carboxyl; group (-COOH) on the other end
chemical reaction
process that changes one set of chemicals into another set of chemicals
reactant
element or compound that enters into a chemical reaction
product
element or compound produced by a chemical reaction
activation energy
energy needed to get a reaction started
catalyst
substance that speeds up the rate of a chemical reaction
enzyme
protein that acts as a biological catalyst
substrate
reactant of an enzyme-catalysts reaction
Describe the functions of each group of organic compounds
carbs-main source of energy; lipids-energy and cell membranes; nucleic acid-store and transmit hereditary information; proteins-control the rate of reactions, regulate cell processes, used to form bones and muscles, help fight disease
Explain how chemical reactions affect chemical bonds in compounds
they break and reform bonds taking in and releasing energy
Describe how energy changes affect how easily a chemical reaction will occur
the higher the activation energy of a reaction the harder it will be for the reaction to occur
Explain why enzymes are important to living things
they decrease activation energy
cell
the basic units of life
cell theory
the idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing ones
nucleus
in cells, structure that contains the cells genetic material (DNA) and controls the cell’s activities
eukaryote
organism whose cells contain nuclei
prokaryote
unicellular organism lacking a nucleus
organelle
specialized structure that preforms important cellular functions within a eukaryotic cell
cytoplasm
material inside the cell membrane – not including the nucleus
nuclear envelope
layer of two membranes that surrounds the nucleus of a cell
chromatin
granular material visible within the nucleus
chromosome
threadlike structure within the nucleus containing the genetic information that is passed from one generation of cells to the next
nucleolus
small, dense region within most nuclei in which the assembly of proteins begins
ribosome
small particle in the cell on which proteins are assembled; made of RNA and protein
endoplasmic reticulum
internal membrane system in cells in which lipid components of the cell membrane are assembled and some proteins are modified
Golgi apparatus
stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum
lysosome
cell organelle filled with enzymes needed to break down materials in the cell
vacuole
cell organelle that stores materials such as water, salts, proteins, and carbohydrates
mitochondrion
cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use
chloroplast
organelle found in cells of plants and some other organisms that captures the energy from sunlight into chemical energy
cytoskeleton
network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement
centriole
one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope
cell membrane
thin, flexible barrier around a cell; regulates what enters and leaves the cell
cell wall
strong supporting layer around the cell membrane in plants, algae, and some bacteria
lipid bilayer
doubled-layered sheet that forms to the core of nearly all cell membranes
concentration
the mass of solute in a given volume of solution, or mass/volume
diffusion
process by which molecules tend to move from and area where they are more concentrated to an area where they are less concentrated
equilibrium
when the concentration of a solute is the same throughout a solution
osmosis
diffusion of water through a selectively permeable membrane
isotonic
when the concentration of two solutions is the same
hypertonic
when comparing two solutions, the solution with the greater concentration of solutes
hypotonic
when comparing two solutions, the solution with the lesser concentration of solutes
facilitated diffusion
movement of specific molecules across cell membranes through protein channels
active transport
energy-requiring process that moves material across a cell membrane against a concentration difference
endocytosis
process by which a cell takes material into the cell by in folding of the cell membrane
phagocytosis
process in which extensions of cytoplasm surround and engulf large particles and take them into the cell
pinocytosis
process by which a cell takes in liquid from the surrounding environment
exocytosis
process by a cell releases large amounts of material
cell specialization
process in which cells develop in different ways to preform different tasks
tissue
group of similar cells that preform a particular task
organ
group of tissues that work together to preform closely related functions
organ system
group of organs that work together to preform a specific function
Explain what the cell theory is
all living things are composed of cells; cells are the basic unit of structure and function in living things; new cells are produced from existing cells
Describe how researchers explore the living cell
by using different microscopes- transmission- see cell structure; scanning- see surface of the cell
Distinguish between eukaryotes and prokaryotes
eukaryote-cell that contain nuclei, organelles, most multicellular organisms; prokaryote-doesn’t contain nuclei, no organelles, unicellular organisms
Describe the function of the cell nucleus
controls activities of organelles; has directions to make proteins
Describe the functions of the major cell organelles
nucleolus- makes ribosomes; ribosomes- assembles proteins; cytoplasm- suspends organelles and site of chemical reactions; endoplasmic reticulum- site of reactions; Golgi apparatus- modifies proteins and sends them to appropriate destinations; vacuole- stores materials; lysosomes- digest excess or worn-out organelles, food, and engulfs viruses and bacteria; chloroplasts- capture light energy and site of photosynthesis; mitochondria- transforms energy in food into ATP; cilia- used to move and obtain food; flagella- propel cells
Identify the main roles of the cytoskeleton
support and maintain shape, movement
Identify the main functions of the cell membrane and the cell wall
cell wall- supports and protects cell; cell membrane- regulates what enters and leaves the cell and also provides protection and support
Describe what happens during diffusion
particles move from an area where they are more concentrated to an area where they are less concentrated
Explain the process of osmosis, facilitated diffusion, and active transport
osmosis- diffusion of water; facilitated diffusion- movement of specific molecules across cell membranes through protein channels; active transport- energy requiring process that moves material across a cell membrane against a concentration difference
Describe cell specialization
cell become specialized for a function in the organism
Identify the organization levels in multicellular organisms
cells, tissues, organs, organ systems
autotroph
organism that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds also called a producer
heterotroph
organism that obtains energy from the food it consumes, also called a consumer
adenosine triphosphate
one of the principle chemical compounds that living things use to store and release energy
photosynthesis
process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high energy carbohydrates such as sugars and starches
chlorophyll
principle pigment of plants and other photosynthetic organisms captures light energy
thylakoid
saclike photosynthetic membrane found in chloroplasts
photosystem
light-collecting units of the chloroplasts
stroma
region outside the thylakiod membranes in chloroplasts
NADP+
one of the carrier molecules that transfers high-energy electrons from chlorophyll to other molecules
light-dependent reactions
reactions of photosynthesis that use energy from light to produce ATP and NADPH
ATP synthase
large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP
Calvin cycle
reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugars
Explain where plants get the energy they need to produce food
sunlight- use photosynthesis into glucose
Describe the role of ATP in cellular activities
easy energy source; energy stored in bonds between second and third phosphate group
State the overall equation for photosynthesis
6CO2+6H2O+light=C6H12O6+6O2
Describe the role of light and chlorophyll in photosynthesis
the pigment chlorophyll traps light in the chloroplasts- light is used to break down H2O for use in the light dependent reaction
Describe the structure and function of a chloroplast
chloroplasts contain granum which are stacks of thylakoid disks; the spaces between and around the granum is known as the stroma; chloroplast is where photosynthesis takes place
Describe what happens in the light-dependent reactions
light energy breaks H2O into H+, O2, and high energy e-; e- is passed down the e- transport chain and eventually makes NADPH; H+ is passed through ATP synthase to form ATP molecules
Explain what the Calvin cycle is
process of forming a 6 carbon carbohydrate from CO2
Identify factors that affect the rate at which photosynthesis occurs
temperature, light intensity, and H2O
calorie
amount of energy needed to raise the temperature of one gram of water by one degree Celsius
glycolysis
first step in releasing the energy of glucose, in which a molecule of glucoseis broken into 2 molecules of pyruvic acid
cellular respiration
process that releases energy by breaking down glucose and other food molecules in the presence of oxygen
NAD+
electron carrier involved in glycolysis
fermentation
process by which cells release energy in the absence of oxygen
anaerobic
process that does not require oxygen
aerobic
process that requires oxygen
Krebs cycle
second stage of cellular respiration, in which pyruvic acid is broken down into carbon dioxide in a series of energy-extractiong reactions
electron transport chain
a series of proteins in which the high-energy electrons from the Krebs cycle are used to convert ADP to ATP
Explain what cellular respiration is
process of changing carbohydrates into energy
Describe what happens during the process of glycolysis
6 carbon carbohydrate is broken down into 2 pyruvic acids; 4 ATP (net 2) and 2 NADH is made
Name the two main types of fermentation
alcoholic and lactic acid
Describe what happens during the Krebs cycle
pyruvic acid combines with a 4 carbon compound, broken apart, and produces 4 NADH, 1 FADH2, and 1 ATP
Explain how high-energy electrons are used by the electron transport chain
high-energy electrons are passed down the e- transport chain causing H+ to flow to the outside of the mitochondrial membrane; as H+ flows n again they pass through ATP synthase creating ATP
Identify the three pathways the body uses to release energy during exercise
lactic acid fermentation, cellular respiration, glycolysis
Compare photosynthesis and cellular respiration
photosynthesis- make glucose, store energy, use CO2 and H2O, gives off O2; respiration- breaks down glucose, releases energy, uses O2, gives off H2O and CO2
cell division
Process by which a cell divides into two new daughter cells
mitosis
Part of eukaryotic cell division during which the cell nucleus divides
cytokinesis
Division of the cytoplasm during cell division
chromatid
1 of 2 sister parts of a duplicated chromosomes
centromere
area where the chromatids of a chromosome are attached
interphase
stage in between cell division
cell cycle
series of events that cells go through as they grew and divides
prophase
first and longest phase of mitosis during which the chromosomes become visible and the centrioles separate and take up opposite sides of the nucleus
centriole
one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope
spindle
fanlike microtubule structure that helps separate the chromosome during mitosis
metaphase
second phase of mitosis, during which the chromosomes line up across the center of the cell
anaphase
the third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles
telophase
fourth and final stage of mitosis, during which the chromosomes begin to disperse into a triangle of dense material
cyclin
one of a family of closely related proteins that regulate the cell cycle in eukaryotic cells
cancer
disorder in which some of the body’s own cells lose the ability to control growth
Explain the problems that growth causes for cells
effective diffusion, not enough DNA, surface area to volume ratio is too great
Describe how cell division solves the problems of cell growth
keeps cell size down
Name the main events of the cell cycle
interphase (G1, S, G2), cell division-mitosis and cytokinesis
Describe what happens during the four phases of mitosis
prophase- chromosomes condense, nucleus disappears, centrioles migrate, spindles form; metaphase- sister chromatids lineup down center; anaphase- sister chromatids split apart and are pulled toward centrioles; telophase- chromatids reach opposite poles, nucleus reforms, chromosomes unwind
Identify a factor that can stop cells from growing
cyclin
Describe how the cell cycle is regulated
by both internal (regulatory proteins) and external (surface proteins) regulators
Explain how cancer cells are different from other cells
they have uncontrolled cell division
genetics
Scientific study of heredity
fertilization
Process in sexual reproduction in which male and female reproductive cells join to form a new cell
true-breeding
Term used to describe organisms that produce offspring identical to themselves if allowed to self-pollinate
trait
Specific characteristics that varies from one individual to another
hybrid
Offspring of crosses between parents with different traits
gene
Sequence of DNA that codes for a protein and thus determines a trait
allele
One of a number of different forms of a gene
segregation
Separation of alleles during gamete formation
gamete
Specialized cell involved in sexual reproduction
probability
Likelihood that a particular event will occur
Punnett square
Diagram showing the gene combinations that might result from a genetic cross
homozygous
Term used to refer to an organism that has two identical alleles for a particular trait
heterozygous
Term used to refer to an organism that has two different alleles for the same trait
phenotype
Physical characteristics of an organism
genotype
Genetic makeup of an organism
independent assortment
Independent segregation of genes during the formation of gametes
incomplete dominance
Situation in which one allele is not completely dominant over another
codominance
Situation in which both alleles of a gene contribute to the phenotype of the organism
multiple alleles
Three or more alleles of the same gene
polygenic traits
Trait controlled by two or more genes
homologous
Term used to refer to chromosomes that have a corresponding chromosome from the opposite-sex parent
diploid
Term used to refer to a cell both sets of homologous chromosomes
haploid
Term used to refer to a cell that contains only a single set of chromosomes and therefore only a single set of chromosomes
meiosis
Process by which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell
tetrad
Structure containing four chromatids that forms during meiosis
crossing-over
Process in which homologous chromosomes exchange portions of their chromatids during meiosis
Describe how Mendel studied inheritance in peas
by crossing pea plants of similar traits
Summarize Mendel’s conclusion about inheritance
traits are inherited from the parent generation- each parent gives 1 alleles
Explain the principle of dominance
some alleles are dominant and others recessive
Describe what happens during segregation
alleles separate independently during gamete formation
Explain how genetics use the principles of probability
use to predict the outcomes of a genetic cross
Describe how genetics use Punnett squares
to predict and compare genetic variations that will result from a cross
Explain the principle of independent assortment
genes of different traits segregate independently during the formation of gametes
Describe other inheritance patterns
incomplete dominance- blending of phenotypes; codominance- both phenotypes expressed; multiple alleles- more than 2 alleles for a trait; polygenic traits- trait controlled by multiple chromosomes
Explain how Mendel’s principles apply to organisms
all organisms follow these same rule and principles for inheritance
Contrast the chromosome number of body cells and gametes
body cells- 2N (diploid); gametes- N (haploid)
Summarize the events of meiosis
meiosis 1- number of chromosomes in each cell splits in half and crossing over occurs (prophase 1) to increase genetic variations; meiosis 2- gametes decrease in size and increase in number
Contrast meiosis and mitosis
Meiosis- 2 phases, chromosomes number decreases, sex cells; mitosis- 1 phase, chromosomes number is same, body cells
nucleotide
monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base
base pairing
principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine
chromatin
granular material visible within the nucleus; consists of DNA tightly coiled around proteins
histone
protein molecule around which DNA is tightly coiled around chromatin
replication
coping process by which a cell duplicates its DNA
DNA polymerase
enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule
gene
sequence of DNA that codes for a protein and thus determines a trait
messenger RNA
RNA molecule that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell
ribosomal RNA
type of RNA that makes up the major part of ribosomes
transfer RNA
type of RNA molecule that transfers amino acids to ribosomes during protein synthesis
transcription
process in which part of the nucleotide sequence of DNA is copied into a complementary sequence in RNA
RNA polymerase
enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription
promoter
region of DNA that indicates to an enzyme where to bind to make RNA
intron
sequence of DNA that is not involved in coding for a protein
exon
expressed sequence of DNA; codes for a protein
codon
three-nucleotide sequence on a messenger RNA that codes for a single amino acid
translation
decoding of mRNA message into a polypeptide chain
anticodon
group of three brothers on a tRNA molecule that are complementary to an mRNA codon
mutation
change in a DNA sequence that affects genetic information
point mutation
gene mutation involving changes in one of a few nucleotide
frameshift mutation
mutation that shifts the “reading” frame of the genetic message by inserting or deleting a nucleotide
polyploidy
condition in which an organism has extra sets of chromosomes
Summarize the relationship between genes and DNA
genes coded by sequences of DNA
Describe the overall structure of the DNA molecule
deoxyribose, phosphate group, nitrogen base
Summarize the events of DNA replication
DNA molecule separates into 2 strands, then 2 new complementary strands following the rule of base pairing; each strand of double helix of DNA serves as a template, or model for the new strand
Relate the DNA molecule to chromosome structure
chromosomes are made of strands of DNA
Tell how RNA differs from DNA
DNA- thymine, double strand, housed in the nucleus; RNA- uracil, single strand, moves in and out of nucleus
Name the three main types of RNA
mRNA- copy made from DNA to take to ribosomes; rRNA- part of ribosome; and tRNA- brings amino acids to ribosomes
Describe transcription and the editing of RNA
RNA copy is made from a DNA strand inside the nucleus
Identify the genetic code
genetic code is made of a sequence of codons
Summarize translation
mRNA codes for specific amino acids which are coded by codons; corresponding anticodons on tRNA carry amino acids attach to mRNA to create a chain of amino acids=protein
Explain the relationship between genes and proteins
genes code for specific proteins
Contrast gene mutations and chromosomal mutations
gene- changes specific codons; chromosomal- changes different genes on chromosomes
selective breeding
method of breeding that allows only those individual organisms with desired characteristics to produce the next generation
hybridization
breeding technique that involves crossing dissimilar individuals to bring together the best traits of both organisms
inbreeding
continued breeding of individuals with similar characteristics to maintain the desired characteristics if a line of organisms
transgenic
term used to refer to an organism that contains genes from other traits
clone
member of a population of genetically identical cells produced from a single cell
karyotype
photograph of chromosomes grouped in order in pairs
sex chromosome
one of two chromosomes that determine an individual’s sex
autosome
chromosome that is not a sex chromosome
pedigree
chart that shows the relationships within a family
sex-linked gene
gene located on the X or Y chromosome
nondisjunction
error in meiosis in which homologous chromosomes fail to separate
DNA fingerprinting
analysis of sections of DNA that have little or no known function, but vary widely from one individual to another, in order to identify individuals
Explain the purpose of selective breeding
carry specific traits
Describe two techniques used in selective breeding
hybridization- crossing dissimilar individuals to bring together the best of both organisms; inbreeding- continue breeding of individuals with similar characteristics
Describe the usefulness of some transgenic organisms to humans
bacteria that can produce human insulin; make larger animals; make healthier plants
Summarize the main steps in cloning
fuse a body cell with the egg of a sheep
Identify the types of human chromosomes in a karyotype
44 autosomes and 2 sex chromosomes
Explain how sex is determined
by sex chromosomes
Explain how pedigrees are used to study human traits
different traits can be tracked down a family tree
Describe examples of the inheritance of human traits
blood group genes (multiple alleles and dominate/recessive)
Explain how small changes in DNA cause genetic disorders
changes in DNA change different proteins that are coded for
Identify characteristics of human chromosomes
omit
Describe some sex-linked disorders and explain why they are more common in males than in females
color blindness; hemophilia; muscular dystrophy; more common in males because even if it is recessive it will be expressed
Explain the process of the X-chromosome inactivation
1 X- chromosome in females is randomly switched off creating a Barr-body
Summarize nondisjunction and the problems it causes
homologous chromosomes fail to separate during the first stage of meiosis; can cause down syndrome (trisomy 21), turners (women with 1 X), and Klinfeltes (man with 2 X’s)
Summarize methods of human DNA analysis
testing for alleles and DNA fingerprinting
State the goal of the Human Genome Project
analyze the human DNA sequence
Describe how researchers are attempting to cure genetic disorders
absent or faulty genes are replaced by working genes
taxonomy
Discipline of classifying organisms and assigning each organism a universally accepted name
binomial nomenclature
Classification system in which each species is assigned a two-part scientific name
taxon
Group or level of organization into which organisms are classified
species
Some description of a characteristic of that animal
genus
Group of closely related species and the first part of the scientific name in binomial nomenclature
family
Group of genera that share many characteristics
order
Group of similar families
class
Group of similar orders
phylum
Group of closely related classes
kingdom
Large taxonomic group, consisting of closely related phyla
phylogeny
Evolutionary relationships among organisms
evolutionary classification
The strategy of grouping organisms together based on their characteristics
derived character
Characteristics that appear in recent parts of a lineage but not in its older members
cladogram
A diagram that shows the evolutionary relationships among a group of organisms
molecular clock
A model that uses DNA comparisons to estimate the length of time that two species have been evolving independently
domain
An inclusive taxonomic category that is bigger than a kingdom
Bacteria
Domain of unicellular prokaryotes that have rigid cell walls containing peptidoglycan
Eubacteria
Kingdom of unicellular prokaryotes whose cell walls are made up of peptidoglycan
Archaea
Domain of unicellular prokaryotes that have cell walls do not contain peptidoglycan and live in extreme environments
Archaebacteria
Kingdom of unicellular prokaryotes whose cell walls do not contain peptidoglycan
Eukarya
Domain of all organisms whose cells have nuclei, including protists, plants, fungi, and animals
Protista
Kingdom composed of eukaryotes that are not classified as plants, animals, or fungi, most diverse, most unicellular (some multicellular), and some photosynthetic, some heterotrophic
Fungi
Kingdom composed of heterotrophs, many obtain energy and nutrients from dead organic matter and most are multicellular (some unicellular)
Plantae
Kingdom of multicellular photosynthetic autotrophs that have cell walls containing cellulose and nonmotile
Animalia
Kingdom of multicellular eukaryotic heterotrophs whose cells do not have cell walls, most can move at some point in their life cycle, and incredible diversity
Explain how living things are organized for study
they are organized into taxons- kingdom, phylum, class, family, genus, species
Describe binomial nomenclature
two word naming system- first word= genus; second word= species
Explain Linnaeus’s system of classification
based on similar characteristics
Explain how evolutionary relationships are important in classification
find out how organisms descended and who they are closely related to
Identify the principle behind cladistic analysis
look at new characteristics as they arrive in a lineage
Explain how we can compare very dissimilar organisms
we can look at DNA and RNA sequences
Name the six kingdoms of life as they are now identified
Eubacteria, Archaebacteria, Protists, Fungi, Plantae, Animalia
Describe the three-domain system of classification
Eubacteria- prokaryote with peptidoglycan in cell wall; Archaebacteria- prokaryote without peptidoglycan in cell wall; Eukarya- eukaryotes
What are the products of photosynthesis?
Oxygen and sugar
The energy of the electrons passing along the electron transport chain is used to make _________.
ATP
Where would you find photosystem I and II?
The thylakoid membrane
What are the products of the Calvin Cycle?
High-energy sugar
Where do light-dependent reactions take place?
Within the thylakoid membrane
If an organisms diploid number is 18, what is it’s haploid number?
9
Cellular respiration uses 1 molecule of glucose to produce _______ molecules of ATP.
36
Which grows faster in a cell, surface area or volume?
volume
_______ is a disorder where the cell loses the ability to control growth and division.
Cancer
What happens to a cell when it comes into contact with another cell?
it stops growing
What is principle of independent assortment?
genes of different traits separate without influence on each other
What are the products of the light dependent reactions?
oxygen gas, ATP, and NADPH
What is the main function of the cytoskeleton?
help the cell keep its shape