Genetics CH. 5 Achieve Quiz
Questions With All Correct Solutions|
2026 Update
Expressivity measures _____ a given allele is expressed at the _____ level.
a. whether; genotypic
b. the degree to which; phenotypic
c. the degree to which; genotypic
d. whether; phenotypic - Ans--b. the degree to which; phenotypic
Beadle and Tatum irradiated the fungus Neurospora to produce mutants
that were defective in some aspect of nutrition. What step did they take next?
a. They tested for single-gene inheritance of the mutation.
b. They did a complementation test.
c. They proposed the one-gene-one-polypeptide hypothesis.
d. They determined which nutrient was deficient, specifically isolating
proline-deficient mutants. - Ans--a. They tested for single-gene inheritance
of the mutation.
When two independently derived recessive mutant alleles producing similar
recessive phenotypes fail to complement, they must be:
a. alleles of different genes.
b. alleles of the same gene.
c. benign mutations.
d. de novo mutations. - Ans--b. alleles of the same gene.
Gene interaction can be inferred from the _____ of double mutants.
a. modifiers
b. heterokaryons
c. phenotypes
d. genotypes - Ans--c. phenotypes
Garrod's observations of alkaptonuria raised the possibility that the cell's
chemical pathways were under the control of a _____ set of _____ genes.
a. small; jumping
,b. similar; protein-encoding
c. diverse; independent
d. large; interacting - Ans--d. large; interacting
To determine the step at which a nonfunctional enzyme blocks a
biosynthetic pathway, _____ can be supplied to cells. The cells will be able
to produce the final product from any step after the block, or where the
nonfunctional enzyme interferes with the pathway.
a. products that occur at different stages of the pathway
b. only precursors
c. precursors involved in a different biosynthetic pathway
d. only the final product - Ans--a. products that occur at different stages of the
pathway
Genetic analysis of gene interaction makes use of _____ alleles, but the
gene interaction revealed is one that is taking place normally in the _____.
a. mutant; wild type
b. wild-type; mutant type
c. leaky; organism
d. null; organism - Ans--a. mutant; wild type
Which of these is TRUE of Beadle and Tatum's experiment?
a. Beadle and Tatum used a haploid organism called Neurospora.
b. Beadle and Tatum used mutants that were able to synthesize all of its
cellular components.
c. Beadle and Tatum analyzed pairs of mutants using the chi-square test.
d. Beadle and Tatum cooked cells to produce auxotrophic mutants. - Ans--a.
Beadle and Tatum used a haploid organism called Neurospora.
A researcher is studying a group of genes that all appear to function in the
same pathway. These genes encode proteins that are involved in multiple
phosphorylation events, and when this pathway is activated, the result is the
transcription of a specific target gene. These genes are most likely involved
in a _____pathway.
a. lethal allele
b. developmental
c. signal-transduction
d. biosynthetic - Ans--c. signal-transduction
, Metabolism is:
a. the synthesis of complex molecules in living organisms from simpler ones
together with the storage of energy.
b. the breakdown of complex molecules in living organisms to form simpler
ones, together with the release of energy.
c. the general set of chemical reactions taking place in an organism.
d. the synthesis of food from carbon dioxide and water. - Ans--c. the general
set of chemical reactions taking place in an organism.
In fruit flies, the wild-type eye color is red. A recessive allele (pd) results in
purple eyes. Another recessive allele (su) of a different gene results in no
apparent phenotype in homozygous flies; however, when two dihybrid
(pd+/pd; su+/su) flies are crossed, the phenotypic ratio of the progeny is
13:3 (red eyes to purple eyes). How would you interpret this result?
a. The su allele is a recessive suppressor of the pd allele.
b. The pd allele is a recessive suppressor of the su allele.
c. The pd allele is only recessively epistatic.
d. The su allele is lethal. - Ans--a. The su allele is a recessive suppressor of
the pd allele.
Gene interaction occurs in all of these cellular pathways EXCEPT:
a. signal transduction pathways.
b. developmental pathways.
c. reaction pathways.
d. biosynthetic pathways. - Ans--c. reaction pathways.
Which of these is a dominant negative mutation?
a. A mutation in the gene encoding collagen, which produces a misshapen
protein that spoils a collagen trimer.
b. A knockout of an allele in mice that produces mice carrying only one allele
copy for a gene of interest.
c. A mutant Tbx1 allele that produces no functional protein and results in
other genes failing to be transcribed, since Tbx1 is a transcription factor.
d. A mutant allele of the phenylketonuria gene that does not produce any
functional PAH enzyme. - Ans--a. A mutation in the gene encoding collagen,
which produces a misshapen protein that spoils a collagen trimer.
Questions With All Correct Solutions|
2026 Update
Expressivity measures _____ a given allele is expressed at the _____ level.
a. whether; genotypic
b. the degree to which; phenotypic
c. the degree to which; genotypic
d. whether; phenotypic - Ans--b. the degree to which; phenotypic
Beadle and Tatum irradiated the fungus Neurospora to produce mutants
that were defective in some aspect of nutrition. What step did they take next?
a. They tested for single-gene inheritance of the mutation.
b. They did a complementation test.
c. They proposed the one-gene-one-polypeptide hypothesis.
d. They determined which nutrient was deficient, specifically isolating
proline-deficient mutants. - Ans--a. They tested for single-gene inheritance
of the mutation.
When two independently derived recessive mutant alleles producing similar
recessive phenotypes fail to complement, they must be:
a. alleles of different genes.
b. alleles of the same gene.
c. benign mutations.
d. de novo mutations. - Ans--b. alleles of the same gene.
Gene interaction can be inferred from the _____ of double mutants.
a. modifiers
b. heterokaryons
c. phenotypes
d. genotypes - Ans--c. phenotypes
Garrod's observations of alkaptonuria raised the possibility that the cell's
chemical pathways were under the control of a _____ set of _____ genes.
a. small; jumping
,b. similar; protein-encoding
c. diverse; independent
d. large; interacting - Ans--d. large; interacting
To determine the step at which a nonfunctional enzyme blocks a
biosynthetic pathway, _____ can be supplied to cells. The cells will be able
to produce the final product from any step after the block, or where the
nonfunctional enzyme interferes with the pathway.
a. products that occur at different stages of the pathway
b. only precursors
c. precursors involved in a different biosynthetic pathway
d. only the final product - Ans--a. products that occur at different stages of the
pathway
Genetic analysis of gene interaction makes use of _____ alleles, but the
gene interaction revealed is one that is taking place normally in the _____.
a. mutant; wild type
b. wild-type; mutant type
c. leaky; organism
d. null; organism - Ans--a. mutant; wild type
Which of these is TRUE of Beadle and Tatum's experiment?
a. Beadle and Tatum used a haploid organism called Neurospora.
b. Beadle and Tatum used mutants that were able to synthesize all of its
cellular components.
c. Beadle and Tatum analyzed pairs of mutants using the chi-square test.
d. Beadle and Tatum cooked cells to produce auxotrophic mutants. - Ans--a.
Beadle and Tatum used a haploid organism called Neurospora.
A researcher is studying a group of genes that all appear to function in the
same pathway. These genes encode proteins that are involved in multiple
phosphorylation events, and when this pathway is activated, the result is the
transcription of a specific target gene. These genes are most likely involved
in a _____pathway.
a. lethal allele
b. developmental
c. signal-transduction
d. biosynthetic - Ans--c. signal-transduction
, Metabolism is:
a. the synthesis of complex molecules in living organisms from simpler ones
together with the storage of energy.
b. the breakdown of complex molecules in living organisms to form simpler
ones, together with the release of energy.
c. the general set of chemical reactions taking place in an organism.
d. the synthesis of food from carbon dioxide and water. - Ans--c. the general
set of chemical reactions taking place in an organism.
In fruit flies, the wild-type eye color is red. A recessive allele (pd) results in
purple eyes. Another recessive allele (su) of a different gene results in no
apparent phenotype in homozygous flies; however, when two dihybrid
(pd+/pd; su+/su) flies are crossed, the phenotypic ratio of the progeny is
13:3 (red eyes to purple eyes). How would you interpret this result?
a. The su allele is a recessive suppressor of the pd allele.
b. The pd allele is a recessive suppressor of the su allele.
c. The pd allele is only recessively epistatic.
d. The su allele is lethal. - Ans--a. The su allele is a recessive suppressor of
the pd allele.
Gene interaction occurs in all of these cellular pathways EXCEPT:
a. signal transduction pathways.
b. developmental pathways.
c. reaction pathways.
d. biosynthetic pathways. - Ans--c. reaction pathways.
Which of these is a dominant negative mutation?
a. A mutation in the gene encoding collagen, which produces a misshapen
protein that spoils a collagen trimer.
b. A knockout of an allele in mice that produces mice carrying only one allele
copy for a gene of interest.
c. A mutant Tbx1 allele that produces no functional protein and results in
other genes failing to be transcribed, since Tbx1 is a transcription factor.
d. A mutant allele of the phenylketonuria gene that does not produce any
functional PAH enzyme. - Ans--a. A mutation in the gene encoding collagen,
which produces a misshapen protein that spoils a collagen trimer.
