Name: __________________________________
Date: ____________________
Study Guide (Part II)
Campbell Biology Unit 4 Evolution
Short Response Questions: (I will choose two of the following short answer prompts
for the Unit 4 Exam Part II)
1. Describe how a plasmid can be genetically modified to include a piece of
foreign DNA that alters the phenotype of bacterial cells transformed with the
modified plasmid. Describe a procedure to determine which bacterial cells
have been successfully transformed.
2. What is the importance of reproductive isolation in Evolution? Describe a few
methods and examples of maintaining reproductive Isolation for
a. Prezygotic Barriers
b. Postzygotic Barriers
3. Discuss the importance of each of the following to Darwin’s Theory of Natural
Selection:
c. Variation among individuals
d. Heritability of traits
e. Competition for Resources
4. Write a short essay evaluating whether changes to an organisms physical
environment are likely to result in evolutionary change. Use examples to
support your reasoning.
Long Response Questions: (I will choose one of the following long answer prompts
for the Unit 4 Exam Part II)
1. Phylogeny is the evolutionary history of a species.
(a) The evolution of a species is dependent on changes in the genome of the
species. Identify TWO mechanisms of genetic change, and explain how each
affects genetic variation.
(b) Based on the data in the table below, draw a phylogenetic tree that
reflects the evolutionary relationships of the organisms based on the
differences in their cytochrome c amino-acid sequences and explain the
relationships of the organisms. Based on the data, identify which organism is
most closely related to the chicken and explain your choice.
(c) Describe TWO types of evidence—other than the comparison of proteins—
that can be used to determine the phylogeny of organisms. Discuss one
strength of each type of evidence you described.
THE NUMBER OF AMINO ACID DIFFERENCES IN CYTOCHROME c
AMONG VARIOUS ORGANISMS
Horse
Horse
Donkey
Chicken
Penguin
Snake
0
Donkey
Chicken
Penguin
Snake
1
11
13
21
0
10
12
20
0
3
18
0
17
0
2. Fossils of lobe-finned fishes, which are ancestors of amphibians, are found in
rocks that are at least 380 million years old. Fossils of the oldest amphibianlike vertebrate animals with true legs and lungs are found in rocks that are
approximately 363 million years old.
Three samples of rocks are available that might contain fossils of a
transitional species between lobe-finned fishes and amphibians: one rock
sample that is 350 million years old, one that is 370 million years old, and
one that is 390 million years old.
(a) Select the most appropriate sample of rocks in which to search for a
transitional species between lobe-finned fishes and amphibians. Justify your
selection.
(b) Describe TWO pieces of evidence provided by fossils of a transitional
species that would support a hypothesis that amphibians evolved from lobefinned fishes.
3. Evolution is one of the unifying themes of biology. Evolution involves change
in the frequencies of alleles in a population. For a particular genetic locus in
a population, the frequency of the recessive allele (a) is 0.4 and the frequency
of the dominant allele (A) is 0.6.
(a) What is the frequency of each genotype (AA, Aa, aa) in this population?
What is the frequency of the dominant phenotype?
(b) How can the Hardy-Weinberg principle of genetic equilibrium be used to
determine whether this population is evolving?
(c) Identify a particular environmental change and describe how it might
alter allelic frequencies in this population. Explain which condition of the
Hardy-Weinberg principle would not be met.