BIO 1108 EXAM QUESTIONS AND
ANSWERS A+ GRADED
Is it possible for 2 red snapdragons from species 1 to have white offspring if they
are both heterozygous?
yes, because heterozygotes are red and if 2 heterozygotes were to cross, 1/4 of their
offspring will be white.
Is it possible for 2 red snapdragons from species 2 to have white offspring if they
are homozygous?
No, because the red ones in species 2 are all homozygous A individuals. That means
none of their offspring will be white. This is an example where species 2 would be
considered to have Incomplete Dominance.
Which of the following traits can evolve within a population due to genetic drift?
trait has to be heritable and variable, genetic drift can also occur on traits that affect
fitness, just because it can evolve with genetic drift doesn't mean it can't also evolve
through natural selection
What is a trait that can't evolve through natural selection?
handedness (not necessarily a fitness advantage)
On the Island of Saba in the Caribbean, there are land crabs that live in the
forests and come out at night to forage for food. In one particular park, there is a
population of 60 crabs. 40 are blue and the other 20 are red. This trait is
controlled by alleles at a single locus. Which of the following statements is true
about this population of crabs?
shell color in this population can evolve (heritability and variability)
What is a trait that cannot undergo evolution?
having feathers when all of the birds have feathers (not variable)
What evolutionary development is occurring when females choose a male based
on the designated territory?
female choice (sexual selection)
Do traits that evolve through sexual selection often result in decreased fitness?
no, sexually selected traits are held by the best breeders
-fitness is not based on how long an individual lives, but how many offspring they have
Over the last 200 years, cheetahs have been hunted to near extinction twice! Both
times populations rebounded somewhat, though they still remain on the
endangered species list. As a result of this intense hunting, their genetic diversity
is very low. The hunters who killed these cheetahs didn't discriminate and just
killed every cheetah they encountered, regardless of how they looked or acted.
Which of the following concepts are illustrated in this description of the history of
cheetah populations in Africa?
genetic drift (random), genetic bottleneck (drastic reduction in population), founders
effect (population rebounded, low genetic diversity)
Currently, hunting pressure is mercifully low on cheetahs. One group of
researchers studying one particular population of cheetahs is interested in how
ANSWERS A+ GRADED
Is it possible for 2 red snapdragons from species 1 to have white offspring if they
are both heterozygous?
yes, because heterozygotes are red and if 2 heterozygotes were to cross, 1/4 of their
offspring will be white.
Is it possible for 2 red snapdragons from species 2 to have white offspring if they
are homozygous?
No, because the red ones in species 2 are all homozygous A individuals. That means
none of their offspring will be white. This is an example where species 2 would be
considered to have Incomplete Dominance.
Which of the following traits can evolve within a population due to genetic drift?
trait has to be heritable and variable, genetic drift can also occur on traits that affect
fitness, just because it can evolve with genetic drift doesn't mean it can't also evolve
through natural selection
What is a trait that can't evolve through natural selection?
handedness (not necessarily a fitness advantage)
On the Island of Saba in the Caribbean, there are land crabs that live in the
forests and come out at night to forage for food. In one particular park, there is a
population of 60 crabs. 40 are blue and the other 20 are red. This trait is
controlled by alleles at a single locus. Which of the following statements is true
about this population of crabs?
shell color in this population can evolve (heritability and variability)
What is a trait that cannot undergo evolution?
having feathers when all of the birds have feathers (not variable)
What evolutionary development is occurring when females choose a male based
on the designated territory?
female choice (sexual selection)
Do traits that evolve through sexual selection often result in decreased fitness?
no, sexually selected traits are held by the best breeders
-fitness is not based on how long an individual lives, but how many offspring they have
Over the last 200 years, cheetahs have been hunted to near extinction twice! Both
times populations rebounded somewhat, though they still remain on the
endangered species list. As a result of this intense hunting, their genetic diversity
is very low. The hunters who killed these cheetahs didn't discriminate and just
killed every cheetah they encountered, regardless of how they looked or acted.
Which of the following concepts are illustrated in this description of the history of
cheetah populations in Africa?
genetic drift (random), genetic bottleneck (drastic reduction in population), founders
effect (population rebounded, low genetic diversity)
Currently, hunting pressure is mercifully low on cheetahs. One group of
researchers studying one particular population of cheetahs is interested in how
