IB 150 Exam 3 Practice Exam Questions With Complete
Solutions
'Maximum parsimony' is a general principle with broad
application in science, which states that: Correct Answers in the
absence of additional information, the explanation that makes
the least unsupported assumptions is the most likely.
A population of 500 jackrabbits has two alleles, FBand FW, for
a locus that codes for fur color. FBFBindividuals have black fur,
FBFW individuals have gray fur,FWFWindividuals have white
fur. 250 individuals are black, 150 individuals are gray and 100
individuals are white. What are the observed genotype
frequencies in this population? Correct Answers 0.50, 0.30,
0.20
A small population of wolves was reintroduced to southern New
Mexico 20 years ago. Within the population at that time were
two different alleles (A1 and A2) for a particular gene that
affects coat color. A recent analysis shows that there is only one
allele (A2) in that population today, after only three generations.
Which of the following mechanisms are potential reasons for
this observation? Correct Answers natural selection AND/OR
genetic drift
A species of seagulls exists as a large number of different
populations on separate islands of the Azores archipelago. Both
black and white gulls are present. The black-colored seagull is
due to a dominant allele (M). Mm and MM individuals are
black, and mm individuals are white. During a storm, two males
and two females are blown 300 miles West, to an isolated island
, uninhabited by seagulls. They reproduce and found a new
population. They cannot disperse back to the original habitat,
nor can any new seagulls cross to the new island. Three of the
original colonists were white-colored gulls and one was black.
Genotyping shows the single black gull to be heterozygous.
What is the frequency of the recessive (m) allele in this new
population? Correct Answers 0.875
A virus killed most of the seals in the North Sea (e.g., reduced
the population from 8000 to 800). What is this an example of?
Correct Answers population bottelneck
All phenotypic traits of an organism are adaptations. Correct
Answers true
Based on the data presented in the previous question, what do
you know for sure? Correct Answers One or more of the five
violations of Hardy-Weinberg must have been acting on this
population within the last generation to cause its genotype
frequencies to deviate from Hardy-Weinberg proportions.
Based on the scenario described at the beginning, and a
comparison of the observed number of individuals to the
expected number of individuals if the population were in Hardy-
Weinberg Equilibrium, which of the following processes is the
most likely to be currently acting on this population of boxers?
Correct Answers Non-random mating - positive assortative
mating
Consider the following graph of body size in a population of
insects in 2008 and 2012:
Solutions
'Maximum parsimony' is a general principle with broad
application in science, which states that: Correct Answers in the
absence of additional information, the explanation that makes
the least unsupported assumptions is the most likely.
A population of 500 jackrabbits has two alleles, FBand FW, for
a locus that codes for fur color. FBFBindividuals have black fur,
FBFW individuals have gray fur,FWFWindividuals have white
fur. 250 individuals are black, 150 individuals are gray and 100
individuals are white. What are the observed genotype
frequencies in this population? Correct Answers 0.50, 0.30,
0.20
A small population of wolves was reintroduced to southern New
Mexico 20 years ago. Within the population at that time were
two different alleles (A1 and A2) for a particular gene that
affects coat color. A recent analysis shows that there is only one
allele (A2) in that population today, after only three generations.
Which of the following mechanisms are potential reasons for
this observation? Correct Answers natural selection AND/OR
genetic drift
A species of seagulls exists as a large number of different
populations on separate islands of the Azores archipelago. Both
black and white gulls are present. The black-colored seagull is
due to a dominant allele (M). Mm and MM individuals are
black, and mm individuals are white. During a storm, two males
and two females are blown 300 miles West, to an isolated island
, uninhabited by seagulls. They reproduce and found a new
population. They cannot disperse back to the original habitat,
nor can any new seagulls cross to the new island. Three of the
original colonists were white-colored gulls and one was black.
Genotyping shows the single black gull to be heterozygous.
What is the frequency of the recessive (m) allele in this new
population? Correct Answers 0.875
A virus killed most of the seals in the North Sea (e.g., reduced
the population from 8000 to 800). What is this an example of?
Correct Answers population bottelneck
All phenotypic traits of an organism are adaptations. Correct
Answers true
Based on the data presented in the previous question, what do
you know for sure? Correct Answers One or more of the five
violations of Hardy-Weinberg must have been acting on this
population within the last generation to cause its genotype
frequencies to deviate from Hardy-Weinberg proportions.
Based on the scenario described at the beginning, and a
comparison of the observed number of individuals to the
expected number of individuals if the population were in Hardy-
Weinberg Equilibrium, which of the following processes is the
most likely to be currently acting on this population of boxers?
Correct Answers Non-random mating - positive assortative
mating
Consider the following graph of body size in a population of
insects in 2008 and 2012:
