Exam Four Sample Exam Questions
1. Speciation, or the formation of new species, is
A) a form of microevolution.
B) responsible for the diversity of life.
C) necessary for natural selection and adaptation.
D) an event that has occurred only a few times in the history of the planet.
2. Speciation without geographic isolation is called ________ speciation.
A) sympatric
B) allopatric
C) incomplete
D) diversifying
3. Which of the following would a biologist describe as microevolution?
A) the formation of new species
B) the extinction of species
C) dramatic biological changes, such as the origin of flight, within a taxon
D) a change in the gene pool of a population from one generation to the next
4. Under the biological species concept, a species is a group of organisms that
A) are physically similar.
B) share a recent common ancestor.
C) live together in a location and carry out identical ecological roles.
D) have the potential to interbreed in nature and produce fertile offspring.
5. Two populations of organisms belong to the same biological species when they
A) cannot mate with each other because mating occurs at different times.
B) use different types of behaviors or physical features to attract mates.
C) have anatomical features that make it difficult for organisms from the two populations to mate
with one another.
D) encounter each other, mate, and produce viable, fertile offspring under natural conditions.
6. Which of the following types of reproductive barriers separates a pair of insect species that could
interbreed but for the fact that one lives on goldenrod plants and the other on autumn daisies in the same
general area?
A) temporal isolation
B) habitat isolation
C) behavioral isolation
D) gametic isolation
7. Two species that occasionally mate and produce zygotes, but that have incompatible genes that prevent
the resulting embryo from developing, are affected by
A) gametic isolation.
B) reduced hybrid fertility.
C) reduced hybrid viability.
D) hybrid breakdown.
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Exam Four Sample Exam Questions
8. Which of the following types of reproductive barriers separates two flowering plant species that could
interbreed but for the fact that one has a deep flower tube and is pollinated by bumblebees whereas the
other has a short, narrow flower tube and is pollinated by honeybees?
a. habitat isolation
b. behavioral isolation
c. mechanical isolation
d. gametic isolation
9. Two species that occasionally mate and produce zygotes, but that have incompatible genes that prevent
the resulting embryo from developing, are affected by
A) gametic isolation.
B) reduced hybrid fertility.
C) reduced hybrid viability.
D) hybrid breakdown.
10. Which of the following processes occurs when a salamander regenerates a lost limb?
A) The homeotic genes of the regenerating limb are expressed.
B) Certain cells in the limb dedifferentiate, divide, and then redifferentiate to form a new limb.
C) A new salamander develops from the lost limb.
D) The homeotic genes of the regenerating cells turn off.
11. Which of the following mammals has not yet been cloned and brought through the complete gestation
cycle?
A) cow
B) human
C) pig
D) cat
12. Adult stem cells have limited therapeutic potential
A) because they are fully differentiated.
B) because they lack a complete set of genes.
C) due to their excessive numbers in tissues.
D) because their developmental potential is limited to certain tissues.
13. Cancer of the colon is caused by
A) a single somatic cell gene mutation.
B) several somatic cell gene mutations.
C) a physical rupture of the colon.
D) a diet high in fiber and low in fat.
14. In terms of gene regulation, what do eukaryotes and prokaryotes have in common?
A) operons such as the lac operon and the trp operon
B) elaborate packing of DNA into chromosomes
C) activator proteins that bind to DNA
D) promoters that bind RNA polymerases
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Exam Four Sample Exam Questions
15. Which of the following statements regarding skin cells and muscle cells in your body is true?
A) Muscle cells contain information about muscle proteins but not about skin color.
B) Skin cells contain information skin color but not about muscle proteins.
C) Muscle cells contain information about skin color but not about muscle proteins.
D) Skin cells and muscle cells each contain information about both muscle proteins and skin
16. We would expect that a 15-nucleotide sequence that includes a stop codon at the end (as part of the
15-nucleotide sequence) will direct the production of a polypeptide that consists of
A) two amino acids.
B) three amino acids.
C) four amino acids.
D) five amino acids.
17. Examine the following two DNA sequences.
Sequence 1:
ATGCGATGCTAGCAT
Sequence 2:
ATGCGATGATAGCAT
If both of these sequences code for proteins, how might the function of protein 2 differ from the function
of protein 1? Use the genetic code below for
assistance.
A) Protein 1 and protein 2 will function exactly the same.
B) Protein 1 will be shorter than protein 2, so they will not function the same.
C) Protein 2 will be shorter than protein 1, so they will not function the same.
D) Protein 2 has a different sequence, so it will function differently from protein 1.
18. A gene operon consists of
A) a transcribed gene only.
B) a promoter only.
C) a regulatory gene only.
D) transcribed genes, an operator, and a promoter.
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Exam Four Sample Exam Questions
19. The lac operon in Escherichia coli
A) prevents lactose-utilizing enzymes from being expressed when lactose is absent from the
environment.
B) prevents lactose intolerance.
C) prevents lactose-utilizing enzymes from being expressed when lactose is present in the
environment.
D) promotes the expression of lactose-utilizing enzymes when lactose is absent from the
environment.
20. The tortoiseshell pattern on a cat
A) usually occurs in males.
B) is the result of a homozygous recessive condition.
C) results from X chromosome inactivation.
D) is a result of alleles on the Y chromosome.
21. The coding regions of a gene are called
A) introns.
B) exons.
C) promoters.
D) enhancers.
22. Which of the following mechanisms of controlling gene expression occurs outside of the nucleus?
A) adding a cap and tail to RNA
B) DNA packing/unpacking
C) RNA splicing
D) translation
23. Which of the following best expresses the concept of natural selection?
A) differential reproductive success based on inherited characteristics
B) inheritance of acquired characteristics
C) change in response to need
D) a process of constant improvement, leading eventually to perfection
24. The recessive allele of a gene causes cystic fibrosis. For this gene among Caucasians, p = 0.98. If a
Caucasian population is in Hardy-Weinberg equilibrium with respect to this gene, what proportion of
babies is born homozygous recessive and therefore suffers cystic fibrosis?
A) (0.02)2 = 0.0004
B) 0.02
C) (0.98)2 = 0.9604
D) 2(0.02 × 0.98) = 0.0392
25. An elk herd is observed over many generations. Most of the full-grown bull elk have antlers of nearly
the same size, although a few have antlers that are significantly larger or smaller than this average size.
The average antler size remains constant over the generations. Which of the following effects probably
accounts for this situation?
A) directional selection
B) stabilizing selection
C) a bottleneck effect that resulted in low genetic diversity
D) a high rate of gene flow
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