BIO 370 Exam 2 QUESTIONS AND
ANSWERS RATED A+ PASSED
random genetic drift (define & who came up with it?) - correct answer ✔✔ changes in allele
frequency caused by the random sampling of genes
Sewell Wright
gene tree - correct answer ✔✔ shows the ancestry of copies of a gene
coalescent events - correct answer ✔✔ branches in a gene tree when more than one copy of an
allele is produced
effective population size - correct answer ✔✔ the size of an idealized population that would
have the same drift as population we are interested in (Ne)
inbreeding load - correct answer ✔✔ the fixation of deleterious mutation by drift due to small
population size
three ways sex is determined and examples of each - correct answer ✔✔ chromosomes--
humans
haplo-diploidy-- in bees, males (unfertilized egg) are haploid and females (fertilized egg) are
diploid
environment-- temperature of eggs in turtles determines sex; clownfish like in hierarchal
society, when the dominant female dies, the dominant males changes sex and takes her place
, parthenogenesis - correct answer ✔✔ asexual reproduction by females making clones of
themselves
Reasons why sexual reproduction should be rare? (4) - correct answer ✔✔ 1. the two-fold cost
of males
2. difficulty finding a mate
3. sexually transmitted diseases
4. sex can break up good combinations of genes (advantageous or selectively favored) by
recombination
What makes sexually reproducing organisms favored over asexual? List the reasons why it is
favored - correct answer ✔✔ Segregation and recombination
1. The Red Queen hypothesis
2. Clonal interference
3. The ruby-in-the-rubbish effect
clonal interference - correct answer ✔✔ SLOWS ADAPTATION IN ASEXUAL ORGANISMS. Two
beneficial mutation arise independently in two asexually producing organisms. They are unable
to combine via recombination and are pitted against each other instead. Competition will lead
to the loss of one of these beneficial mutations.
ruby-in-the-rubbish effect - correct answer ✔✔ beneficial mutations are lost in asexual
populations because they are linked to deleterious mutations (hitch-hiking)
gene flow - correct answer ✔✔ the movement of individuals that changes gene frequency in a
population; must involve the mixing of two populations together
ANSWERS RATED A+ PASSED
random genetic drift (define & who came up with it?) - correct answer ✔✔ changes in allele
frequency caused by the random sampling of genes
Sewell Wright
gene tree - correct answer ✔✔ shows the ancestry of copies of a gene
coalescent events - correct answer ✔✔ branches in a gene tree when more than one copy of an
allele is produced
effective population size - correct answer ✔✔ the size of an idealized population that would
have the same drift as population we are interested in (Ne)
inbreeding load - correct answer ✔✔ the fixation of deleterious mutation by drift due to small
population size
three ways sex is determined and examples of each - correct answer ✔✔ chromosomes--
humans
haplo-diploidy-- in bees, males (unfertilized egg) are haploid and females (fertilized egg) are
diploid
environment-- temperature of eggs in turtles determines sex; clownfish like in hierarchal
society, when the dominant female dies, the dominant males changes sex and takes her place
, parthenogenesis - correct answer ✔✔ asexual reproduction by females making clones of
themselves
Reasons why sexual reproduction should be rare? (4) - correct answer ✔✔ 1. the two-fold cost
of males
2. difficulty finding a mate
3. sexually transmitted diseases
4. sex can break up good combinations of genes (advantageous or selectively favored) by
recombination
What makes sexually reproducing organisms favored over asexual? List the reasons why it is
favored - correct answer ✔✔ Segregation and recombination
1. The Red Queen hypothesis
2. Clonal interference
3. The ruby-in-the-rubbish effect
clonal interference - correct answer ✔✔ SLOWS ADAPTATION IN ASEXUAL ORGANISMS. Two
beneficial mutation arise independently in two asexually producing organisms. They are unable
to combine via recombination and are pitted against each other instead. Competition will lead
to the loss of one of these beneficial mutations.
ruby-in-the-rubbish effect - correct answer ✔✔ beneficial mutations are lost in asexual
populations because they are linked to deleterious mutations (hitch-hiking)
gene flow - correct answer ✔✔ the movement of individuals that changes gene frequency in a
population; must involve the mixing of two populations together
