Biology EOC Review 22-23

ecology

scientific study of interactions among organisms and between organisms and their environment

biosphere

part of Earth in which life exists including land, water, and air or atmosphere

species

group of similar organisms that can breed and produce fertile offspring

population

group of individuals of the same species that live in the same area

community

assemblages of different populations that live together in a defined area

ecosystem

collection of all the organisms that live in a particular place, together with their nonliving environment

biome

group of ecosystems that have the same climate and dominant communities

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

producer

organism that can capture energy from sunlight or chemicals and use it to produce food from inorganic compounds; also called an autotroph

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

heterotroph

organism that obtains energy from the foods it consumes; also called a consumer

consumer

organism that relies on other organisms for its energy and food supply; also called a heterotroph

herbivore

organism that obtains energy by eating only plants

carnivore

organism that obtains energy by eating animals

omnivore

organism that obtains energy by eating both plants and animals

detritivore

organism that feeds on plant and animal remains and other dead matter

decomposer

organism that breaks down and obtains energy from dead organic matter

food chain

series of steps in an ecosystem in which organisms transfer energy by eating and being eaten

food web

network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem

trophic level

step in a food chain or food web

ecological pyramid

diagram that shows the relative amounts of energy or matter within each trophic level in a food chain or food web

biomass

total amount of living tissue within a given trophic level

evaporation

process by which water changes from a liquid into an atmospheric gas

transpiration

loss of water from a plant through its leaves

cilia

short hairlike projection similar to a flagellum; produces movement in many cells

contractile vacuole

Cavity in the cytoplasm of some protists that collects water and discharges it from the cell

prokaryote

unicellular organism lacking a nucleus

genetic equilibrium

situation in which allele frequencies remain constant

evolution

change in a kind of organism over time; process by which modern organisms have descended from ancient organisms

theory

well-tested explanation that unifies a broad range of observations

artificial selection

selection by humans for breeding of useful traits from natural variation

struggle for existence

competition among members of a species for food, living space, and the other necessities of life

fitness

ability of an organism to survive and reproduce in its environment

adaptation

inherited characteristic that increases an organism's chance of survival

survival of the fittest

process by which the individuals that are better suited to their environment survive and reproduce most successfully; also called natural selection

natural selection

process by which the individuals that are better suited to their environment survive and reproduce most successfully; also called survival of the fittest

nucleotide

building block of a nucleic acid (DNA and RNA)

base pairing

Adenine+ Thymine, Cytosine+ Guanine

chromatin

long strands of DNA found in the eukaryotic cell nucleus; condense to form chromosomes

replication

(genetics) the process whereby DNA makes a copy of itself before cell division

DNA polymerase

enzyme that makes bonds between nucleotides, forming an identical strand of DNA during replication

gene

sequence of DNA that codes for a protein and thus determines a trait

mRNA (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

tRNA (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

codon

three-nucleotide sequence on messenger RNA that codes for a single amino acid

translation

decoding of a mRNA message into a polypeptide chain

mutation

a change or alteration in form or qualities

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

sex-linked genes

genes found on the chromosomes that determine sex, XX\= female, XY\= male

homologous

term used to refer to chromosomes that each have a corresponding chromosome from the opposite-sex parent

diploid

term used to refer to a cell that contains 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 genes

meiosis

process by which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell

crossing-over

process in which homologous chromosomes exchange portions of their chromatids during meiosis

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

one of two identical "sister" parts of a duplicated chromosome

centromere

area where the chromatids of a chromosome are attached

interphase

period of the cell cycle between cell divisions

cell cycle

series of events that cells go through as they grow and divide

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

centriole

one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope

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 phase of mitosis, during which the chromosomes begin to disperse into a tangle of dense material

cancer

disorder in which some of the body's own cells lose the ability to control growth

homologous

term used to refer to chromosomes that each have a corresponding chromosome from the opposite-sex parent

diploid

term used to refer to a cell that contains 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 genes

meiosis

process by which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell

crossing-over

process in which homologous chromosomes exchange portions of their chromatids during meiosis

protein synthesis

The process in which amino acids are arranged in a linear sequence through the processes of transcription of DNA and to RNA and the translation of RNA to a polypeptide chain.

chromosome

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

karyotype

A display of the chromosome pairs of a cell arranged by size and shape.

genetics

The scientific study of heredity

punnet square

A chart that shows all the possible combinations of alleles that can result from a genetic cross

heterozygous

An organism that has two different alleles for a trait

homozygous

An organism that has two identical alleles for a trait

dominant

Describes a trait that covers over, or dominates, another form of that trait.

recessive

An allele that is masked when a dominant allele is present

hybrid

An organism that has two different alleles for a trait

1:2:1

genotype ratio of a Aa X Aa cross

3:1

phenotype ratio of a Aa X Aa cross

phenotype

An organism's physical appearance, or visible traits.

genotype

An organism's genetic makeup, or allele combinations.

allele

An alternative form of a gene.

protein

A molecule that is made up of amino acids and that is needed to build and repair body structures and to regulate processes in the body.

carbohydrate

Class of energy giving nutrients that include starches, fibers and sugars

lipid

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.

photosynthesis

6CO2 + 6H2O + light --\> C6H12O6 + 6O2

cellular respiration

(Uses) Glucose + Oxygen --\> (Makes) Carbon Dioxide + Water + Energy

carbon cycle

the recycling of carbon through photosynthesis, respiration, and decomposition in living things in an ecosystem

water cycle

The continual movement of water among Earth's atmosphere, oceans, and land surface through evaporation, condensation, and precipitation

cell membrane

A cell structure that controls which substances can enter or leave the cell.

phospholipid bilayer

Plasma membrane layers composed of phospholipid molecules arranged with polar heads facing the outside and nonpolar tails facing the inside.

mitochondria

An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur.

chloroplast

(in green plant cells) a plastid that contains chlorophyll and in which photosynthesis takes place.