17.1 and 17.2 Flashcards Preview

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Flashcards in 17.1 and 17.2 Deck (13):
1

gene pool

all the genes, including all the different alleles for each gene, that are present in a population at any one time

2

allele frequency

the number of times that an allele occurs in a gene pool compared with the number of alleles in that pool for the same gene

3

single-gene trait

trait controlled by one gene that has two alleles

4

polygenic trait

trait controlled by two or more genes

5

directional selection

form of natural selection when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve

6

stabilizing selection

form of natural selection in which individuals near the center of a distribution curve have higher fitness than individuals at either end of the curve

7

disruptive selection

natural selection in which individuals at the upper and lower end of the curve have higher fitness than individuals near the middle of the curve

8

genetic drift

random change in allele frequency caused by a series of chance concurrences that cause an allele to become more or less common in a population

9

bottleneck effect

a change in allele frequency following a dramatic reduction in size of a population

10

founder effect

change in allele frequencies a a result of the migration of a small subgroup of a population

11

genetic equilibrium

situation in which allele frequencies in a population remain the same

12

Hardy-Weinberg Principle

principle that states that allele frequencies in a population remain constant unless one or more factors cause those frequencies to change

13

sexual selection

when individuals select mates based on heritable traits