Biol 1107 Exam 5 Study Guide
Table of Contents
1. Practice Exam 3. Top Hat Questions
2. Quizelt Review 4. Homework #1
Practice Exam
Key
My Answer
Correct Teacher Answer
1. Hemophilia is an X-linked recessive disorder that is characterized by excessive bleeding.
What is the frequency of the recessive allele in a population that include 853 homozygous
dominant females, 149 carrier females, 2 affected famles, 965 unaffected males, and 27
affected males?
(149 + (2*2) + 27)/ (2008 +992) = 0.06
Females have 2 copies of a gene on the X chromosome, but males have only one
copy. There are 1,004 females and 992 males in the population, so there are (1,004*2) + 992
= 3,000 total copies of the gene. There are 149 (from carrier females) + 4 (from affected
females) + 27 (from affected males) = 180 total copies of the recessive allele, so its
frequency is 180/3,000 = 0.06
2. Assume hair color is controlled by 1 gene with 2 alleles in reindeer, and brown is dominant
to white. A population in Hardy-Weinberg equilibrium that includes 588 brown and 112
white individuals migrates to join another population in equilibrium that includes 357 brown
and 343 white individuals. How many reindeer in the combined population are homozygous
dominant?
945 brown and 455 white reindeer in the population now so there are a total of
1400 reindeer. We know that q2 = (455/1400) = 0.325 so that q = 0.57. We can then
find p by subtracting 1 -0.57 to find that p = 0.43 and p2 = 0.1849. We can then use
these values to determine the number of heterozygour reindeer by doing 2pq or
2(0.57)(0.43) = 0.4902. To find the total number of reindeer we then multiply that by
1400 to get 686.28 heterozygour reindeer. We can then find the total number of
homozygous dominant reindeer by subtracting 945-686.28 to find that there are a
total of 258 homozygous dominant reindeer in the population
, Both population are in equilibrium, so the Hardy-Weinberg model can be applied
individually to each one. Hardy-Weinberg be used for the combined population due to the
migration.
Population 1 → q2 = [112/(588+112)] = 0.16 → q = 0.4 → p = 1 - 0.4 = 0.6 → p2 = 0.36
Population 2 → q2 = [343/(357+343)] = 0.49 → q = 0.7 → p = 1 - 0.7 = 0.3 → p2 = 0.09
Number of homozygous dominant reindeer = [0.36*(588+112)] + [0.09*(357+343)] = 315
3. Identity the prezygotic barriers that result in rpeoructive isolation for the following species
Species Prezgotic Barrier
Monterey and bishop pines are both native to california Temporal
but release their pollen during different times of the year Temporal isolation
Pacific and caribbean species of snapping shrimp were Geographical
separated when a new landmass formed (now panama) Geographic isolation
Different species of damselflies are unable to interbreed Mechanical
due to the incompatible anatomies of males and females Mechanical isolation
African savannah and forest elephants live in the same Ecological
areas but prefer different habitats and rarely interbreed Ecological isolation
Eastern and western meadowlarks look identical to each Behavioral
other but do not interbreed due to their distinctive songs Behvioral isolation
Red sea urchins and purple sea urchins live in the same Gametic
ocean habitat but produce incompatible sperm and eggs Gametic isolation
4. Gray treefrogs are tetrapolid animals that are native to north america. Southern gray
treefrogs are identical in appearance and live in the same areas and habitats but are diploid.
a. Explain how the difference in ploidy between these 2 treefrog species leads to their
repdoructive isolation
Their ploidy differences still allow them to produce an offspring but
their offsprings are not fertile casuing them not to be able to reproduce
Tetraploid (4n) and diploid (2n) parents would have triploid (3n) offspring
that will be infertile (hybrid sterility) or will not survive (hybrid inviability). Hybrid
sterility occurs in the treefrogs
b. Which species concept was likely used to classify the treefrogs as different species
You could use biological species concept since the frogs when bred
together do not produce fertile offsprings
These treefrogs are the same species under the morphological species
concept, but the inability to produce fertile offspinrgs makes them different species
under the biological species concept
5. Evolution, selection, and adaptions are often mistaken for each other. Explain the
differences
, Selection is the cause of eveoltuion because selection is a mechanism that
favors certain traits or animals causing evolution. Adaptions are the produce of
eveoltuion because animals in a population have to adapt to the changing conditions
that are caused by evolution
Evolution is a change in allele frequencies of a population over time, selection is a
mechanism that causes evolution, and adaptions are traits that are found in population due
to selection
6. Use the phylogenetic tree of reptiles and birds shown below to answer the following
questions
a. Magpie geese, kakapos, and princess parrots are bird species, while the other animals
on the phylogenetic tree are reptiles. Do the birds form a monophyletic group? Do
the reptiles form a monophyletic group? Would the birds and reptiles together be a
monophyletic group
The birds by themselves would be a monophyletic group because they
all came from the same recent common ancestor. Because of this we also
know that the reptiles do not form a monophyletic group because they do not
all come from the same recent common ancestor. When combined both the
birds and reptiles do form a monophyletic groups because they do all come
from the same recent common ancestor
Monophyletic groups consist of a common ancestor and all descendants.
Birds decenended from a common ancestor and form a monophyletic group. Reptile
(as traditionally defined) are not a monophyletic group unless birds are also
considered reptiles
b. Are smiling terrapins (turtle species from asia) more closely related to a copperhead
(snake species from north america) or a kakapo (flightless bird species from new
zealand)
They would be more closely related to kakapos because of the first
node and they are closer together in terms of being related
Based on the phylogenetic tree, smiliing terapins are more closely related to
kakapos, since the species share a more recent common ancestor than smiling
terrapins and copperheads
Table of Contents
1. Practice Exam 3. Top Hat Questions
2. Quizelt Review 4. Homework #1
Practice Exam
Key
My Answer
Correct Teacher Answer
1. Hemophilia is an X-linked recessive disorder that is characterized by excessive bleeding.
What is the frequency of the recessive allele in a population that include 853 homozygous
dominant females, 149 carrier females, 2 affected famles, 965 unaffected males, and 27
affected males?
(149 + (2*2) + 27)/ (2008 +992) = 0.06
Females have 2 copies of a gene on the X chromosome, but males have only one
copy. There are 1,004 females and 992 males in the population, so there are (1,004*2) + 992
= 3,000 total copies of the gene. There are 149 (from carrier females) + 4 (from affected
females) + 27 (from affected males) = 180 total copies of the recessive allele, so its
frequency is 180/3,000 = 0.06
2. Assume hair color is controlled by 1 gene with 2 alleles in reindeer, and brown is dominant
to white. A population in Hardy-Weinberg equilibrium that includes 588 brown and 112
white individuals migrates to join another population in equilibrium that includes 357 brown
and 343 white individuals. How many reindeer in the combined population are homozygous
dominant?
945 brown and 455 white reindeer in the population now so there are a total of
1400 reindeer. We know that q2 = (455/1400) = 0.325 so that q = 0.57. We can then
find p by subtracting 1 -0.57 to find that p = 0.43 and p2 = 0.1849. We can then use
these values to determine the number of heterozygour reindeer by doing 2pq or
2(0.57)(0.43) = 0.4902. To find the total number of reindeer we then multiply that by
1400 to get 686.28 heterozygour reindeer. We can then find the total number of
homozygous dominant reindeer by subtracting 945-686.28 to find that there are a
total of 258 homozygous dominant reindeer in the population
, Both population are in equilibrium, so the Hardy-Weinberg model can be applied
individually to each one. Hardy-Weinberg be used for the combined population due to the
migration.
Population 1 → q2 = [112/(588+112)] = 0.16 → q = 0.4 → p = 1 - 0.4 = 0.6 → p2 = 0.36
Population 2 → q2 = [343/(357+343)] = 0.49 → q = 0.7 → p = 1 - 0.7 = 0.3 → p2 = 0.09
Number of homozygous dominant reindeer = [0.36*(588+112)] + [0.09*(357+343)] = 315
3. Identity the prezygotic barriers that result in rpeoructive isolation for the following species
Species Prezgotic Barrier
Monterey and bishop pines are both native to california Temporal
but release their pollen during different times of the year Temporal isolation
Pacific and caribbean species of snapping shrimp were Geographical
separated when a new landmass formed (now panama) Geographic isolation
Different species of damselflies are unable to interbreed Mechanical
due to the incompatible anatomies of males and females Mechanical isolation
African savannah and forest elephants live in the same Ecological
areas but prefer different habitats and rarely interbreed Ecological isolation
Eastern and western meadowlarks look identical to each Behavioral
other but do not interbreed due to their distinctive songs Behvioral isolation
Red sea urchins and purple sea urchins live in the same Gametic
ocean habitat but produce incompatible sperm and eggs Gametic isolation
4. Gray treefrogs are tetrapolid animals that are native to north america. Southern gray
treefrogs are identical in appearance and live in the same areas and habitats but are diploid.
a. Explain how the difference in ploidy between these 2 treefrog species leads to their
repdoructive isolation
Their ploidy differences still allow them to produce an offspring but
their offsprings are not fertile casuing them not to be able to reproduce
Tetraploid (4n) and diploid (2n) parents would have triploid (3n) offspring
that will be infertile (hybrid sterility) or will not survive (hybrid inviability). Hybrid
sterility occurs in the treefrogs
b. Which species concept was likely used to classify the treefrogs as different species
You could use biological species concept since the frogs when bred
together do not produce fertile offsprings
These treefrogs are the same species under the morphological species
concept, but the inability to produce fertile offspinrgs makes them different species
under the biological species concept
5. Evolution, selection, and adaptions are often mistaken for each other. Explain the
differences
, Selection is the cause of eveoltuion because selection is a mechanism that
favors certain traits or animals causing evolution. Adaptions are the produce of
eveoltuion because animals in a population have to adapt to the changing conditions
that are caused by evolution
Evolution is a change in allele frequencies of a population over time, selection is a
mechanism that causes evolution, and adaptions are traits that are found in population due
to selection
6. Use the phylogenetic tree of reptiles and birds shown below to answer the following
questions
a. Magpie geese, kakapos, and princess parrots are bird species, while the other animals
on the phylogenetic tree are reptiles. Do the birds form a monophyletic group? Do
the reptiles form a monophyletic group? Would the birds and reptiles together be a
monophyletic group
The birds by themselves would be a monophyletic group because they
all came from the same recent common ancestor. Because of this we also
know that the reptiles do not form a monophyletic group because they do not
all come from the same recent common ancestor. When combined both the
birds and reptiles do form a monophyletic groups because they do all come
from the same recent common ancestor
Monophyletic groups consist of a common ancestor and all descendants.
Birds decenended from a common ancestor and form a monophyletic group. Reptile
(as traditionally defined) are not a monophyletic group unless birds are also
considered reptiles
b. Are smiling terrapins (turtle species from asia) more closely related to a copperhead
(snake species from north america) or a kakapo (flightless bird species from new
zealand)
They would be more closely related to kakapos because of the first
node and they are closer together in terms of being related
Based on the phylogenetic tree, smiliing terapins are more closely related to
kakapos, since the species share a more recent common ancestor than smiling
terrapins and copperheads
