Biology Final 2Nd Semester

Front 1

Evolution

Back 1

change over time, is the process by which modern organisms have decended from ancient organisms.

Front 2

Theory

Back 2

is a well-supported testable explination of phenomena that have occured in the natural world.

Front 3

Fossils

Back 3

preserved remains of an ancient oranism.

Front 4

Artificial selection

Back 4

nature provided the variation, and humans selected those variaions that they found useful.

Front 5

Struggle for existance

Back 5

members of each species compete regularly to obtain food, living space, and other necesities of life.

Front 6

Adaptation

Back 6

ant inherited characteristic that increases and organism's chance of survival.

Front 7

Fitness

Back 7

an organism's ability to reproduce.

Front 8

Survival of the fittest

Back 8

when the organism has high levels of finess and is better suited for its enviorment.

Front 9

Natural selection

Back 9

process by which individuals that are better suited for thier enviorment survive and reproduce most sucsessfully; also calles survival of the fittest.

Front 10

Descent with modification

Back 10

each living species has a descended, with changes, from other species over time.

Front 11

Common descent

Back 11

princible that all living things were derived from common ancestors.

Front 12

homologous sructures

Back 12

structures that have different mature forms but develop from the same embryonic tissues.

Front 13

Vestigia organs

Back 13

the organs of many animal s are so reduced in size that they are just vestiges, or taces, of homologous organs in other species.

Front 14

Gene Pool

Back 14

combined genetic information of all the members of a particular population.

Front 15

Reletive frequency

Back 15

number of times an allele occurs in a gene pool compared with the number of times other alleles occur.

Front 16

Single-gene trait

Back 16

trait controlled by a single gene that has two alleles.

Front 17

Polygenic trait

Back 17

trait controlled by two or more genes.

Front 18

Stabilizing selection

Back 18

form of natural selection by which the center of the curve remains in its current form; occurs when individuals near the center of a distrabution curve have higher fitness than individuals at the other end.

Front 19

Distruptive selection

Back 19

form of natural selection in which a Single curve splits into two; occurs when individuals at the upper and lower ends of a distrabution curve have higher fitness than individuals near the middle

Front 20

Genetic drift

Back 20

Random change in allele frequencies that occurs in small populations.

Front 21

Founder affect

Back 21

Change in allele frequencies as a result of the immigration of a small subgroup of a population.

Front 22

Hardy-weinberg principle

Back 22

principle that allele frequencies in a population will remain constant unless one or more factors cause the frequencies to change.

Front 23

Genetic equillibrium

Back 23

situation in which allele frequencies remain constant.

Front 24

Speciation

Back 24

formation of new species

Front 25

Reproductive isolation

Back 25

seperation of species or populations so that they cannot be interbred and produce ferttle offspring.

Front 26

Behaviaral isolation

Back 26

form of reproductive isolation in which two populations have differences in courtship rituals or other types of behavior that prevent them from inter breeding.

Front 27

Geographic isolation

Back 27

form of reproductive isolation in which two populations are seperated physically by geographical barriers such as rivers, mountains, stretches of water.

Front 28

Temporal Isolation

Back 28

form of reproductive isolation in which two populations reproduce different times.