BIO 148 EXAM 3 QUESTIONS &
ANSWERS
Evolution can be defined as
Individuals becoming better adapted whenever the environment changes
Only the fittest survive
One species changing into another
Genetic change over time within a population - Correct Answers -Genetic change over
time within a population
For evolution to occur, which of the following is/are necessary?
I. Heritable variation
II. Selection
III. Environmental change
I, II, and III
II only
I and II
I only - Correct Answers -I only
Which of the following mutations is most likely to increase fitness?
A silent mutation in an essential gene
A frameshift mutation in the gene that encodes DNA polymerase
A missense mutation that increases activity of an enzyme - Correct Answers -A
missense mutation that increases activity of an enzyme
A mutation that confers antibiotic resistance to bacteria occurs in a large population of
bacteria growing in a test tube without antibiotic. The same mutation occurs in a
bacterial population growing in the presence of an antibiotic. After many generations,
the number of antibiotic resistant bacteria in the tube without antibiotic is:
much lower than the number in the tube containing antibiotic
about the same as the number in the tube containing antibiotic
impossible to determine - Correct Answers -much lower than the number in the tube
containing antibiotic
Which evolutionary force is the slowest to change allele frequencies on its own?
mutation
natural selection
gene flow
genetic drift - Correct Answers -mutation
An individual that is heterozygous for a particular gene has ____________.
, Two identical alleles of the gene, with each copy located on different non-homologous
chromosomes
Two different alleles of the gene, with each copy located on different non-homologous
chromosomes
Two different alleles of the gene, with each copy located on homologous chromosomes
Two identical alleles of the gene, with each copy located on homologous chromosomes
- Correct Answers -Two different alleles of the gene, with each copy located on
homologous chromosomes
Which of these descriptions correctly describes metaphase II of meiosis?
Cell is diploid, chromosomes line up in center
Cell is haploid, chromosomes line up in center
Cell is haploid, sister chromosomes separate
Cell is diploid, homologs pair
Cell is haploid, homologs pair - Correct Answers -Cell is haploid, chromosomes line up
in center
A cell that is the product of meiosis II and cytokinesis contains the chromosomes shown
below. Which of the following would be present in the sperm that develops from this
cell? - Correct Answers -b.
You have isolated a single cell from a diploid organism. Which of the following would
indicate that the cell was at metaphase of meiosis I and NOT metaphase of meiosis II?
There was only one copy of each type of chromosome
All the chromosomes were composed of one chromatid
All the chromosomes were composed of two chromatids
Homologous chromosomes were present
It has a metaphase plate - Correct Answers -Homologous chromosomes were present
The A and B genes are on the same chromosome. A zygote is formed by the fusion of a
gamete with the genotype aB and a gamete with the genotype Ab. Which of the
following accurately depicts the chromosome content of the zygote right after
fertilization occurs? - Correct Answers -d.
The diploid organism Biologica isawesema has 10 TOTAL chromosomes in each of its
body (somatic) cells. If a cell from this organism divides by meiosis, the cells formed by
meiosis I and cytokinesis will have _____ CHROMOSOMES and _____ DNA
MOLECULES.
10, 10
5, 10
5, 5
20, 20
10, 20 - Correct Answers -5, 10
ANSWERS
Evolution can be defined as
Individuals becoming better adapted whenever the environment changes
Only the fittest survive
One species changing into another
Genetic change over time within a population - Correct Answers -Genetic change over
time within a population
For evolution to occur, which of the following is/are necessary?
I. Heritable variation
II. Selection
III. Environmental change
I, II, and III
II only
I and II
I only - Correct Answers -I only
Which of the following mutations is most likely to increase fitness?
A silent mutation in an essential gene
A frameshift mutation in the gene that encodes DNA polymerase
A missense mutation that increases activity of an enzyme - Correct Answers -A
missense mutation that increases activity of an enzyme
A mutation that confers antibiotic resistance to bacteria occurs in a large population of
bacteria growing in a test tube without antibiotic. The same mutation occurs in a
bacterial population growing in the presence of an antibiotic. After many generations,
the number of antibiotic resistant bacteria in the tube without antibiotic is:
much lower than the number in the tube containing antibiotic
about the same as the number in the tube containing antibiotic
impossible to determine - Correct Answers -much lower than the number in the tube
containing antibiotic
Which evolutionary force is the slowest to change allele frequencies on its own?
mutation
natural selection
gene flow
genetic drift - Correct Answers -mutation
An individual that is heterozygous for a particular gene has ____________.
, Two identical alleles of the gene, with each copy located on different non-homologous
chromosomes
Two different alleles of the gene, with each copy located on different non-homologous
chromosomes
Two different alleles of the gene, with each copy located on homologous chromosomes
Two identical alleles of the gene, with each copy located on homologous chromosomes
- Correct Answers -Two different alleles of the gene, with each copy located on
homologous chromosomes
Which of these descriptions correctly describes metaphase II of meiosis?
Cell is diploid, chromosomes line up in center
Cell is haploid, chromosomes line up in center
Cell is haploid, sister chromosomes separate
Cell is diploid, homologs pair
Cell is haploid, homologs pair - Correct Answers -Cell is haploid, chromosomes line up
in center
A cell that is the product of meiosis II and cytokinesis contains the chromosomes shown
below. Which of the following would be present in the sperm that develops from this
cell? - Correct Answers -b.
You have isolated a single cell from a diploid organism. Which of the following would
indicate that the cell was at metaphase of meiosis I and NOT metaphase of meiosis II?
There was only one copy of each type of chromosome
All the chromosomes were composed of one chromatid
All the chromosomes were composed of two chromatids
Homologous chromosomes were present
It has a metaphase plate - Correct Answers -Homologous chromosomes were present
The A and B genes are on the same chromosome. A zygote is formed by the fusion of a
gamete with the genotype aB and a gamete with the genotype Ab. Which of the
following accurately depicts the chromosome content of the zygote right after
fertilization occurs? - Correct Answers -d.
The diploid organism Biologica isawesema has 10 TOTAL chromosomes in each of its
body (somatic) cells. If a cell from this organism divides by meiosis, the cells formed by
meiosis I and cytokinesis will have _____ CHROMOSOMES and _____ DNA
MOLECULES.
10, 10
5, 10
5, 5
20, 20
10, 20 - Correct Answers -5, 10
