Biology Final Review

catastrophism

natural disasters shape landforms and cause mass extinctions

gradualism

changes in landforms were due to slow changes over a long period of time

uniformitarianism

geological processes are constant and ongoing

variation

difference in a physical trait

adaptation

an inherited feature that allow an organism to better survive in its enviroment

artificial selection

the process by which humans select trait through breeding

natural selection

mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals

heritability

the ability of a trait to be passed to offspring

fitness

the measure of survival ability and ability to produces more offspring

struggle for survival/ differential survival

some in a population will have a phenotypic advantage

selective pressure/ enviromental change

a changing envirmonet will favor some phenotypes over others

permineralization

occurs when minerals carried by water are deposited around a hard structure

natural cast

forms when flowing water removes all of the original tissue leaving an impression

trace fossils

record the activity of an organism

amber-preserved

fossils are organisms that become trapped in tree resin that hardens after the tree is buried

preserved remains

form when an organism becomes encased in material such as ice

radiometric dating

provides an accurate way to estimate the age of fossils using decay of unstable isotopes

relative dating

estimates the time whihc an orgaims lived

index fossils

used to determine the age of rock layers

vestigial structures

remnants or organs or structures that had a function in a early ancestor

structural patterns

clues to the history of a species

homologous structures

similar in structure but different in function and indicate evidence of a common ancestor

analogous structures

similar function; not evidence of a common ancestor

paleontology

study of fossils or extinct organisms; provides evidence to support evolution

hox genes

control the development of specific structures found in many organisms

allele frequency

how common an allele is in a population; measure of genetic variation

evolution

change in relative frequency of alleles in a population

gene

part of a chromosome that determines a trait; composed of DNA

genotype

the set of genes an organims carries

phenotype

observable characteristics

allele

form of a gene; inherited from parents

mutations

a random change in the DNA of a gene; produce genetic variation

recombination

forms new combinations of different alleles

gene flow

the movement of alleles between populations

sexual selection

occurs when certain traits increase mating success

genetic drift

change in allele frequencies due to chance

natural selection

selects for traits advantageous for survival

reproductive isolation

can occur between isolated populations

behavioral isolation

includes differences in mating behavior

geographic isolation

physical barries that divide populations

temporal isolation

timing of reproductive period prevents mating

convergent evolution

desribes evolution toward similar traits in unrelated species

divergent evolution

describes evolution toward different traits in closely related species

coevolution

two or more species evolve in response to changes in each other

punctuated equilibrium

episodes of speciation occur suddenly in geologic time followed by long period of little evolutionary change

adaptive radiation

many species evolve from one species

binomial nomenclature

two-part scientific naming system

genus

includes one or more physically similar species

species

descriptor is the second part of a scientific name

phylogeny

the evolutionary history of an organism

cladistics

classification based on common ancestry

cladogram

type of evolutionary tree made using cladistics

derived characters

traits shared in different degrees by clade members

nodes

represent the most recent common ancestro of a clade

chlorophyll

a molecule that absorbs light energy; found in chloroplasts

pigments

molecules that abosrb certain wavelengths of lights

light dependent reactions

occurs in thylakoids of chloroplasts and capture energy from sunlight

light independent reactions/ calvin cycle

takes places in stroma of chloroplasts and makes sugars

glycolysis

takes place in the cytoplasm; does not require oxygen

krebs cycle

transfers energy to an electron transport chain; takes place in the mitochondrial matrix

ETC

where most of ATP is produced; takes place in inner membrane

ecology

the study of the relationships among organisms and their enviroment

population

group of the same spceies that lives in one area

organism

individual living thing

community

group of adifferent species that live together in one area

ecosystem

includes all of the organisms as well as abiotic factors

biome

a major regional globlas community of organisms characterized by the climate conditions

biotic factors

living things in an ecosystem

abiotic factors

nonliving factors in an ecosystem

biodiversity

the assotment or variety of living things in an ecosystem

keystone system

species that has an unusually large on its ecosytem

herbivores

eat only plants

carnivores

eat only animals

omnivores

eath both plants and animals

detrivores

eat dead organic matter

decomposers

detrivores that break down organic matter into simpler compounds

primary consumer

herbivores that eat producers

secondary consumers

carnivores that eat herbivores

tertiary consumer

carnivores that eat secondary consumers

biomass

measure of the total dry mass of organisms in given area

habitat

all aspects of the area in which an organism lives

ecological niche

includes all of the factors that s species needs to survive, stay healthy, and reproduce

competitive exclusion

keeps two speceis from occupting the same niche

ecological equivalents

species that occupy similar niches but live in different geographical regions

competition

occurs when two organims fight for the same limited resource

intrasecific competition

between the same species

interspecific competition

between two different species

predation

occurs when one organism captures and eats another

mutualism

both organisms benefit

commensalism

one organism benefits the other is unharmed

parasitism

one organism benefits the other is harmed

exponential growth

rapid population increase due to an abundance of resources

logistic growth

due to a population facing limited resources

carrying capacity

the maximum number of individuals in a population that the enviroment can support

population crash

dramatic decline in the size of a population over a short period of time

limiting factor

something that keeps the zise of a population down

density dependent limiting factors

affected by the number of individuals ina given area

density independent limitng factors

limit a population’s growth regardless of the density

succession

a process of change in the species that make up a community