models of selection

Question 1

complete dominance

Answer 1

dominant allele masks the effect of the recessive allele (EX. red RR x white rr = red Rr)

Question 2

partial / incomplete dominance

Answer 2

both alleles of a gene are expressed resulting in an intermediate phenotype (red RR x white rr = pink Rr)

Question 3

underdominance

Answer 3

when the heterozygote (AB) allele is less fit than the homozygote (AA, BB) alleles

Question 4

overdominance

Answer 4

heterozygotes have a higher fitness than homozygotes

Question 5

positive frequency dependent selection

Answer 5

the more common a phenotype is, the higher its fitness becomes. natural selection (ex. species deterring predators with color patterns)

Question 6

negative frequency dependent selection

Answer 6

rarer phenotypes have a higher fitness

Question 7

directional selection

Answer 7

favors one extreme trait, is against the other extreme trait

Question 8

stabilizing selection

Answer 8

favors the moderate (average trait), against both extreme traits

Question 9

disruptive selection

Answer 9

favors both extreme traits, against the moderate trait