BIOLOGY EOC REVIEW
Terms
Definitions
activation energy
energy needed to start a chemical reaction; lowered by enzymes
active transport
movement of molecules across a membrane requiring energy to be expended by the cell
adaptation
inherited characteristic that increases an organism's chance of survival
allele
the different forms of a gene; could be dominant or recessive
amino acid
basic building blocks of proteins
analogous
structures that do not have a common evolutionary origin but are similar in form or
structures
function
anaphase
the third phase of mitosis, during which the chromosome pairs separate and move
toward opposite poles
antibiotic
antibody
compound that blocks the growth and reproduction of bacteria
a substance produced by the body that destroys or inactivates a pathogen that has
entered the body
antigen
substance (usually foreign) that stimulates the production of an antibody
archaea
domain of unicellular prokaryotes that have cell walls that do not contain peptidoglycan
ATP
a nucleotide that stores and transfers energy within cells
autotroph
organism that can capture energy from sunlight or chemicals and use it to produce its
own food; also called a producer
bacteria
domain of unicellular prokaryotes that have cell walls containing peptidoglycans
bacteriophage
virus that infects bacteria
base deletion
mutation which results in the loss of nucleotide pairs in a gene; have a major effect on
the resulting protein
base insertion
mutation which results in the addition of nucleotide pairs in a gene; have a major effect
on the resulting protein
base-pair
a type of point mutation where one nucleotide and its partner are replaced by another
substitution
pair of nucleotides
behavioral
an inherited behavior that helps an organism survive; like escaping from predators or find
adaptation
a mate
binary fission
asexual reproduction in prokaryotes by which one cell divides into two identical cells
fetus
an unborn or unhatched vertebrate in the later stages of development showing the main
recognizable features of the mature animal
fever
a rise in the temperature of the body
fitness
the ability of an individual to survive and reproduce in its specific environment
food chain
a series of steps in which organisms transfer energy by eating and being eaten
food web
a diagram that shows the feeding relationships between organisms in an ecosystem
fossil
the remains (or an impression) of a plant or animal that existed in a past geological age
and that has been excavated from the soil
gamete
egg or sperm sex cell that contains a single set of chromosomes (haploid), one from
each homologous pair
gene
sequence of DNA that codes for a protein and thus determines a trait
binomial
Classification system in which each species is assigned a two-part scientific name
nomenclature
including the genus and species
biodiversity
the variety of different species in a given area
biogeochemical
process in which elements, chemical compounds, and other forms of matter are passed
cycle
from one organism to another and from one part of the biosphere to another; like the
carbon and nitrogen cycle
biomass
the total amount of living matter within a given trophic level
capsid
the outer covering of protein surrounding the nucleic acid of a virus
carbohydrate
organic compound used by cells to store and release energy; composed of carbon,
hydrogen, and oxygen
carbon cycle
the organic circulation of carbon from the atmosphere into organisms and back again
carnivore
a consumer that only eats other consumers
catalyst
substance that speeds up the rate of a chemical reaction; like an enzyme
cell
basic unit of life
cell cycle
the cycle of growth and reproduction of a cell, consisting of interphase (g1, s, g2) and
mitosis (division of the nucleus-prophase, metaphase, anaphase, and telophase) and
cytokinesis (division of cytoplasm)
cell division
the process by which a cell divides into two new daughter cells
cell membrane
The lipid bilayer that forms the outer boundary of the cell
cell wall
a rigid structure that surrounds the cell membrane and provides support to the cell; made
of carbohydrates
cellular respiration
process that releases energy by breaking down glucose and other food molecules in the
presence of oxygen
centriole
organize the spindle fibers to separate chromosomes during animal cell mitosis
centromere
area where the chromatids of a chromosome are attached
chlorophyll
green pigment in plants that absorbs light energy used to carry out photosynthesis
chloroplast
organelle found in cells of plants and some other organisms that captures the energy
from sunlight and converts it into chemical energy
chromatid
one of two identical "sister" parts of a duplicated chromosome
gradualism
a model of evolution in which gradual change over a long period of time leads to
biological diversity
guard cell
Pairs of cells that surround stomata and control their opening and closing.
habitat
the place where an organism lives
haploid number
half the normal number of chromosomes; found in sex cells
herbivore
consumer that eats only producers; also called a primary consumer
heterozygous
having two different alleles for a trait
homeostasis
process by which organisms maintain a relatively stable internal environment
chromosome
condensed threads of genetic material formed from chromatin as a cell prepares to
divide
climax community
a relatively stable long-lasting community reached in a successional series
codon
in RNA, a three-base "word" that codes for one amino acid
commensalism
symbiotic relationship in which one member of the association benefits and the other is
neither helped nor harmed
competition
the struggle between organisms to survive in a habitat with limited resources
concentration
difference in concentration of a substance on two sides of a membrane
gradient
conclusion
a summary of what you have learned from an experiment
consumer
an organism that obtains energy by feeding on other organisms
crossing over
exchange of genetic material between homologous chromosomes during prophase I of
meiosis
cytokinesis
division of the cytoplasm
cytoplasm
a jellylike fluid inside the cell in which the organelles are suspended
data
information gathered from observations
decomposer
organism that breaks down and obtains energy from dead organic matter
deforestation
the removal of trees
differentiation
process in which cells become specialized in structure and function
diffusion
the process by which molecules move from an area of higher concentration to an area of
lower concentration; passive
dihybrid cross
genetic cross using two traits with two alleles each
diploid number
cell condition in which two of each type of chromosome are present
disturbance
A discrete event that disrupts an ecosystem or community. Examples of natural
disturbances include fires, hurricanes, tornadoes, droughts, and floods. Examples of
human-caused disturbances include deforestation, overgrazing, and plowing.
DNA
deoxyribonucleic acid, the material that contains the information that determines
inherited characteristics
kingdom
large taxonomic group, consisting of closely related phyla
learned behavior
a behavior an animal learns from its parents
lipid
macromolecule made mainly from carbon and hydrogen atoms; includes fats, oils, and
waxes
lysosome
cell organelle filled with enzymes needed to break down certain materials in the cell
macromolecule
any large complex organic molecule
meiosis
Cell division that produces reproductive cells in sexually reproducing organisms
mRNA
messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the
ribosome
metaphase
second phase of mitosis, during which the chromosomes line up across the center of the
cell
domain
Most inclusive taxonomic category; larger than a kingdom
dominant
trait that will show up in an organism's phenotype if gene is present
double helix
two strands of nucleotides wound about each other; structure of DNA
ecological
gradual change in living communities that follows a disturbance
succession
ecosystem
living and nonliving things in an environment, together with their interactions
egg
Female sex cell
embryo
organism in its early stage of development
embryology
study of multicellular organisms as they develop from fertilized eggs to fully formed
organisms
endocytosis
process by which a cell takes in a substance by surrounding it with the cell membrane;
active transport
endoplasmic
a system of membranes that is found in a cell's cytoplasm and that assists in the
reticulum
production, processing, and transport of proteins and in the production of lipids
energy pyramid
a diagram that shows the amount of energy that moves from one feeding level to another
in a food web
enzyme
protein that speeds up a chemical reaction
equilibrium
When the concentration of a solute is the same throughout a solution
eukaryote
A cell that contains a nucleus and membrane bound organelles
eutrophication
rapid growth of algae in bodies of water, due to high levels of nitrogen and often
phosphate
evolution
the gradual change in a species over time
exocytosis
process by which vesicles release their contents outside the cell; active transport
experiment
the act of conducting a controlled test or investigation
facilitated diffusion
movement of specific molecules across cell membranes through protein channels;
passive transport
fertilization
the joining of a sperm cell and an egg cell
nucleic acid
a long chain of smaller molecules called nucleotides; DNA and RNA
nucleotide
monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a
nitrogenous base
nucleus
a part of the cell containing DNA responsible for growth and reproduction
omnivore
organism that obtains energy by eating both plants and animals
organ
a collection of tissues that carry out a specialized function of the body
organ system
group of organs that work together to perform a specific function
organelle
a tiny cell structure that carries out a specific function within the cell
organism
a living thing that has (or can develop) the ability to act or function independently
gene flow
movement of alleles into or out of a population due to the migration of individuals to or
from the population
gene pool
all of the alleles in all the individuals that make up a population
generation
one step in the line of descent of a family
genetic
new combination of genetic information in a gamete as a result of crossing over during
recombination
prophase I of meiosis
genetics
the branch of biology that studies heredity and variation in organisms
genome
the complete genetic material contained in an individual
genotype
genetic makeup of an organism; like BB, Bb, or bb
genus
taxonomic group containing one or more species
geology
science dealing with the earth's history as recorded in rocks
geotropism
response to the earth's gravity, as the growing of roots downward in the ground
glycolysis
first step in releasing the energy of glucose, in which a molecule of glucose is broken into
two molecules of pyruvic acid.
golgi body
a structure in a cell that receives proteins and other newly formed materials from the
endoplasmic reticulum, packages them, and transports them out of the cell
pollution
Release of harmful materials into the environment
predation
an interaction in which one organism captures and feeds on another organism
primary consumer
consumer that feeds directly on producers
primary
the series of changes that occur in an area where no soil or organisms exist
succession
producer
an organism that can make its own food
prokaryote
A unicellular organism that LACKS a nucleus and membrane bound organelles
recessive
The inherited characteristic often masked by the dominant characteristic and not seen in
an organism.
replication
(genetics) the process whereby DNA makes a copy of itself before cell division
reproductive
separation of species or populations so that they cannot interbreed and produce fertile
isolation
offspring
resistance
the degree of unresponsiveness of a disease-causing microorganism to antibiotics or
other drugs (as in penicillin-resistant bacteria)
response
a bodily process occurring due to the effect of some stimulus or agent
ribosome
An organelle that functions in the synthesis of proteins
RNA
ribonucleic acid; a nucleic acid that plays an important role in the production of proteins
secondary
consumer that eats primary consumers
consumer
spindle
tiny fibers that are seen in cell division
stimulus
a signal to which an organism responds
stomata
Small openings on the underside of a leaf through which oxygen and carbon dioxide can
move.
homologous
Chromosomes that are similar in size, shape, and genetic content
chromosomes
homologous
Structures in different species that are similar because of common ancestry.
structures
homozygous
having two identical alleles for a trait
hormone
substance produced in one part of an organism that affects another part of the same
organism
hydrotropism
a plants growth response to water; plant grows towards the water
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
independent
the random distribution of the pairs of genes on different chromosomes to the gametes
assortment
infectious disease
A disease that is caused by a pathogen and that can be spread from one individual to
another.
instinct
a behavior that an organism inherits
isotonic
when the concentration of two solutions is the same
keystone species
a species that influences the survival of many other species in an ecosystem
secondary
succession following a disturbance that destroys a community without destroying the soil
succession
seed
a mature fertilized plant ovule consisting of an embryo and its food source and having a
protective coat
selectively
a property of cell membranes that allows some substances to pass through, while others
permeable
cannot
somatic cell
Any cell in a multicellular organism except a sperm or egg cell.
speciation
the formation of new species as a result of evolution
species
taxonomic group whose members can interbreed
structural
a physical feature of an organism's body having a specific function that contributes to the
adaptation
survival of the organism
substrate
The reactant on which an enzyme works.
symbiosis
relationship in which two species live closely together
taxonomy
a classification of organisms into groups based on similarities of structure or origin etc
telophase
the final stage of meiosis when the chromosomes move toward opposite ends of the
nuclear spindle
theory
well-tested explanation that unifies a broad range of observations
thigmotropism
plant growth in response to touch
transpiration
loss of water from a plant through its leaves
trophic level
feeding level in an ecosystem
tropism
the growth response of a plant toward or away from a stimulus
vaccine
substance prepared from killed or weakened pathogens and introduced into a body to
produce immunity
mitochondria
cellular organelles where cellular respiration occurs
mitosis
part of eukaryotic cell division during which the cell nucleus divides
monohybrid cross
a cross in which only one characteristic is tracked
mutagen
physical or chemical agent that causes mutations
mutation
change in a DNA sequence that affects genetic information
mutualism
symbiotic relationship in which both species benefit from the relationship
natural resource
materials found in nature that are used by living things
natural selection
process by which individuals that are better suited to their environment survive and
reproduce most successfully; also called survival of the fittest
negative feedback
mechanism of homeostasis that tends to stabilize a process by reducing its rate or output
niche
the status of an organism within its environment and community (affecting its survival as
a species)
nitrogen cycle
the transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to
the atmosphere
nuclear membrane
controls what goes in and out of the nucleus
tissue
group of similar cells that perform a particular function
toxin
a poison that can harm an organism
trait
a characteristic that an organism can pass on to its offspring through its genes.
transcription
process where the DNA sequence in a gene is copied into mRNA
tRNA
transfer RNA; type of RNA that carries amino acids to the ribosome
translation
decoding of a mRNA message into a polypeptide chain
vacuole
cell organelle that stores materials such as water, salts, proteins, and carbohydrates
variation
differences between organisms
vascular tissue
tissue that conducts water and nutrients through the plant body in plants
vestigial structure
parts of an organism that are no longer functioning and do not affect survival
virus
package of nucleic acid wrapped in a protein coat that must use a host cell's machinery
to reproduce itself
xylem
the vascular tissue through which water and nutrients move in plants
zygote
fertilized egg
osmosis
diffusion of water through a selectively permeable membrane
parasitism
symbiotic relationship in which one organism lives in or on another organism (the host)
and consequently harms it
passive transport
The movement of materials through a cell membrane without using energy
pathogen
disease-causing agent
phenotype
physical characteristics of an organism; like green eyes, bushy tail or sleek tail
phloem
the vascular tissue through which food moves in plants
photosynthesis
process by which plants and some other organisms use light energy to convert water and
carbon dioxide into oxygen and carbohydrates
phototropism
phylogenetic tree
Plant growth in response to light
diagram showing evolutionary relationships of organisms with a common ancestor;
resembles a tree
phylogeny
The study of evolutionary relationships among organisms
pioneer species
first species to populate an area during primary succession
pollination
transfer of pollen from the anther to the stigma of a plant
prophase
first and longest phase of mitosis, during which the chromosomes become visible and
the centrioles separate and take up positions on the opposite sides of the nucleus
protein
macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the
body for growth and repair and to make up enzymes
protein synthesis
the formation of proteins by using information contained in DNA and carried by mRNA
protist
single-celled or simple multicellular eukaryotic organisms that generally do not fit in any
other kingdom
punctuated
pattern of evolution in which long stable periods are interrupted by brief periods of more
equilibrium
rapid change
Punnett square
a chart that shows all the possible combinations of alleles that can result from a genetic
cross