Chapter 10: Population Genetics and Evolution Flashcards Preview

AP Biology > Chapter 10: Population Genetics and Evolution > Flashcards

Flashcards in Chapter 10: Population Genetics and Evolution Deck (39):
1

evolution

the change in a population's gene pool from one generation to the next

2

quantitative characteristics

traits in a population that vary along a continuum

3

gene pool

all the collective genes of a population

4

population

all the members of the same species within a given area

5

non-evolving population

a hypothetical collection of individuals in a given area whose gene pool does not change from generation to generation

6

genotype

the allelic composition for a particular trait

7

alleles

different forms of a given gene

8

homozygous

having two identical alleles for a given trait

9

Tay-Sachs disease

a genetically based disease characterized by a dysfunctional enzyme that fails to break down brain lipids, and is expressed in the homozygous recessive condition

10

sickle-cell anemia

a disease characterized by defective red blood cells that are inefficient in carrying oxygen

11

microevolution

changes in genetic structure (genotype) of a population

12

genetic drift

changes in the gene pool of a small population due to chance

13

mutation

a change in an organism's DNA that can result in a permanent change in the allele

14

natural selection

differential success in the reproduction of different phenotypes resulting from the interaction of organisms with their environment

15

gene flow

changes in the gene pool due to migration of fertile individuals or gametes

16

non-random mating

when an individual chooses a mate based on specific criteria

17

polymorphism

the occurrence of two or more distinct forms of members of a population

18

dimorphism

two different morphs

19

stabilizing selection

extremes are selected against, and the average is selected for

20

directional selection

one extreme is selected for, and the opposite extreme is selected against

21

diversifying selection

extremes are selected for, and the average is selected against

22

natural selection

the process where organisms of differing phenotypes interact with their environment which results in differential reproductive success

23

biological species concept

two organisms are in the same species when they can produce fertile, viable offspring in free-ranging conditions

24

morphological species concept

classifies species based on anatomical differences

25

recognition species concept

classifies species based upon their courtship rituals (genetic, morphological, and behavioral) and mate selection

26

cohesion species concept

classifies species based upon the mechanisms they use to maintain the phenotypic integrity of the population (ex: reproductive barriers such as pre and post-zygotic isolation)

27

polyploid

having more than two complete sets of chromosomes (2n)

28

ecological species concept

classifies species based on their ecological niche or role in the environment (where they live, what they do, and how they look)

29

allopatric speciation

physical isolation resulting from a geographic barrier separates a splinter population from a main population

30

marsupial

mammals characterized by embryonic development in a pouch

31

placental

mammals characterized by embryonic development in a uterus

32

adaptive radiation

a great increase in species diversity over a relatively short time, each variation adapting to a new or unused resources or habit

33

sympatric speciation

formation of a new species from a subpopulation while physically located amongst the parent population

34

autopolyploidy

having more than 2n sets of chromosomes, all of which derived from the same species, and can occur through self-fertilization

35

nondisjunction

a mistake during cell division in which either pairs of homologous chromosomes or sister chromatids fail to separate properly

36

allopolyploidy

having more than 2n sets of chromosomes which are derived from two different species

37

meiotic errors

mistakes that occur during gamete formation that result in cells with an incorrect number of chromosomes

38

transition fossils

preserved, extinct life forms that show the link between a new species and its parent species

39

balanced polymorphism

the ability of natural selection to promote diversity in a population