Question 1

Which Drosophila individual must be hemizygous?

Accepted Answer

A)  A male for an allele at an autosomal locus 
B)  A female for an allele at an autosomal locus 
C)  A male for an allele at an X-linked locus 
D)  A female for an allele at an X-linked locus 
E)  It is impossible to say without experimental data. 
A)  A male for an allele at an autosomal locus 
B)  A female for an allele at an autosomal locus 
C)  A male for an allele at an X-linked locus 
D)  A female for an allele at an X-linked locus 
E)  It is impossible to say without experimental data. C

Question 2

A test cross of a pea plant with round and yellow seeds yields half round, yellow seeds and half round, green seeds.You conclude that the plant was homozygous for the shape gene and _______ for the color gene.

Accepted Answer

heterozygous

Question 3

One true-breeding line of mice is obese and dark, and the other true-breeding line is lean and light.Dark is dominant to light, but obese and lean exhibit incomplete dominance.The two genes involved are on separate chromosomes.What proportion of offspring from a dihybrid cross should be dark and obese?

Accepted Answer

A)  1/16 
B)  3/16 
C)  1/4 
D)  3/8 
E)  9/16 
A)  1/16 
B)  3/16 
C)  1/4 
D)  3/8 
E)  9/16 B

Question 4

Refer to the figure showing a family pedigree and recessive inheritance.Note the mother in generation I is a carrier of a rare recessive autosomal trait.   What is the probability that a member of generation III will be a carrier of this trait?

Accepted Answer

A)  0.1 
B)  0.25 
C)  0.5 
D)  0.75 
E)  1 
A)  0.1 
B)  0.25 
C)  0.5 
D)  0.75 
E)  1

Question 5

A woman has B blood type of the ABO system.Her mother is type O.From this, we can infer that her father

Accepted Answer

A)  has AB blood type. 
B)  could not have AB blood type. 
C)  could not have B blood type. 
D)  could not have O blood type. 
E)  could be any blood type. 
A)  has AB blood type. 
B)  could not have AB blood type. 
C)  could not have B blood type. 
D)  could not have O blood type. 
E)  could be any blood type.

Question 6

A population of Drosophila simulans carries three alleles at the white locus: the wild-type allele at 86 percent, w1 at 9 percent, and w2 at 5 percent.What can we say about this population?

Accepted Answer

A)  There must be other alleles that have not been sampled. 
B)  The population is polymorphic. 
C)  w1 must be dominant to w2. 
D)  w2 must be dominant to w1. 
E)  The white locus has pleiotropic effects. 
A)  There must be other alleles that have not been sampled. 
B)  The population is polymorphic. 
C)  w1 must be dominant to w2. 
D)  w2 must be dominant to w1. 
E)  The white locus has pleiotropic effects.

Question 7

Egg and Fluffy are two linked bird genes that are 16 map units apart.The E allele of Egg produces large eggs, and the e allele produces small eggs (E is dominant).The F allele produces fluffy feathers, and the f allele produces nonfluffy feathers (F is dominant).If EeFf is crossed with eeff, what proportion of the offspring should be birds that produce small eggs and fluffy feathers? (Note: Assume that the parents of EeFf were EEFF and eeff.)

Accepted Answer

A)  8 percent 
B)  16 percent 
C)  42 percent 
D)  84 percent 
E)  100 percent 
A)  8 percent 
B)  16 percent 
C)  42 percent 
D)  84 percent 
E)  100 percent

Question 8

In Drosophila, three autosomal genes have alleles as follows: Normal bristles (Sb) is dominant over stubble bristles (sb); straight wings (C) is dominant over curly wings (c); and red eye (Se) is dominant over sepia (se).Two test crosses were performed, with the results shown in the table.   What linkage can you determine from these crosses?

Accepted Answer

A)  Only Se and Sb are linked, with a distance of 32.2 units. 
B)  Only Sb and C are linked, with a distance of 48.7 units. 
C)  Only Se and C are linked, with a distance of 40.7 units. 
D)  None of the genes are linked. 
E)  All of the genes are on the same chromosome, Se and Sb are 32.2 units apart, and Sb and C are 48.7 units apart. 
A)  Only Se and Sb are linked, with a distance of 32.2 units. 
B)  Only Sb and C are linked, with a distance of 48.7 units. 
C)  Only Se and C are linked, with a distance of 40.7 units. 
D)  None of the genes are linked. 
E)  All of the genes are on the same chromosome, Se and Sb are 32.2 units apart, and Sb and C are 48.7 units apart.

Question 9

A(n) _______ cross involves two different unlinked genes, each affecting a different character.

Accepted Answer

A)  monohybrid 
B)  dihybrid 
C)  trihybrid 
D)  F1 
E)  F2 
A)  monohybrid 
B)  dihybrid 
C)  trihybrid 
D)  F1 
E)  F2

Question 10

What distinguishes the phenotypes of the different ABO groups?

Accepted Answer

A)  Different proteins on the surfaces of red blood cells 
B)  Different proteins inside red blood cells 
C)  Different nucleic acids on the surfaces of red blood cells 
D)  Different oligosaccharides inside red blood cells 
E)  Different oligosaccharides on the surfaces of red blood cells 
A)  Different proteins on the surfaces of red blood cells 
B)  Different proteins inside red blood cells 
C)  Different nucleic acids on the surfaces of red blood cells 
D)  Different oligosaccharides inside red blood cells 
E)  Different oligosaccharides on the surfaces of red blood cells

Question 11

Nearly all male wasps in natural populations of the species Nasonia vitripenis have small wings.The trait of small wings in this species is thus considered

Accepted Answer

A)  polymorphic. 
B)  dominant. 
C)  codominant. 
D)  a genotype. 
E)  the wild type. 
A)  polymorphic. 
B)  dominant. 
C)  codominant. 
D)  a genotype. 
E)  the wild type.

Question 12

In cattle, hybrids often are more reproductively fit than the purebreds.Suppose that this increased vigor in hybrids, or heterosis, is due mainly to the lack of inbreeding depression.This would then support the _______ hypothesis.

Accepted Answer

The answer of In cattle, hybrids often are more reproductively...

Question 13

Consider the F2 progeny of a dihybrid cross.For every double recessive homozygote observed, you should expect _______ double dominant homozygote(s).

Accepted Answer

A)  1/9 
B)  1/3 
C)  1 
D)  3 
E)  9 
A)  1/9 
B)  1/3 
C)  1 
D)  3 
E)  9

Question 14

The ABO blood groups in humans are determined by a multiple-allele system in which IA and IB are codominant and are both dominant to IO.A newborn infant is type A.The mother is type O.Possible phenotypes of the father are

Accepted Answer

A)  A, B, or AB. 
B)  A, B, or O. 
C)  O only. 
D)  A or AB. 
E)  A or O. 
A)  A, B, or AB. 
B)  A, B, or O. 
C)  O only. 
D)  A or AB. 
E)  A or O.

Question 15

In humans, which chromosome is inherited only from the mother?

Accepted Answer

A)  Autosomes 
B)  X chromosome 
C)  Y chromosome 
D)  Mitochondria 
E)  All of the above are inherited from both the mother and the father. 
A)  Autosomes 
B)  X chromosome 
C)  Y chromosome 
D)  Mitochondria 
E)  All of the above are inherited from both the mother and the father.

Question 16

In tomatoes, tall is dominant to dwarf, and smooth fruits are dominant to hairy fruits.A plant that is homozygous for both dominant traits is crossed with a plant that is homozygous for both recessive traits.Crosses of the F1 progeny yield the following results: 78 tall smooth fruits, 82 dwarf hairy fruits, 22 tall hairy fruits, and 18 dwarf smooth fruits.These data indicate that the genes are

Accepted Answer

A)  on different chromosomes. 
B)  linked, but do not cross over. 
C)  linked and show 10 percent recombination. 
D)  linked and show 20 percent recombination. 
E)  linked and show 40 percent recombination. 
A)  on different chromosomes. 
B)  linked, but do not cross over. 
C)  linked and show 10 percent recombination. 
D)  linked and show 20 percent recombination. 
E)  linked and show 40 percent recombination.

Question 17

When analyzing Drosophila offspring of test crosses to determine gene linkage, what value for recombination frequency would tell you that two genes are probably not linked?

Accepted Answer

A)  0.00 
B)  0.25 
C)  0.50 
D)  1.00 
E)  1.50 
A)  0.00 
B)  0.25 
C)  0.50 
D)  1.00 
E)  1.50

Question 18

Wild type fruit flies have red eyes.A white-eyed female fly is crossed with a red-eyed male fly.All of the females from the cross are red-eyed, and all of the males are white-eyed.What type of inheritance pattern is this?

Accepted Answer

A)  Independent assortment 
B)  Autosomal dominant 
C)  Autosomal recessive 
D)  Incomplete dominance 
E)  Sex-linked 
A)  Independent assortment 
B)  Autosomal dominant 
C)  Autosomal recessive 
D)  Incomplete dominance 
E)  Sex-linked

Question 19

Sickle cell anemia is a disease that causes red blood cells to clump.It often leads to blood clots and strokes, among other conditions.Although sickle cell anemia is due to a recessive allele and nearly all homozygous individuals have the disease, its effects vary, as some individuals with the disease can live fairly normal lives well into middle age, and others die in infancy.Based on the above, which statement about sickle cell anemia is true?

Accepted Answer

A)  It shows low penetrance. 
B)  It exhibits epistasis. 
C)  It exhibits variable expressivity. 
D)  It is a result of heterosis. 
E)  It shows quantitative variation. 
A)  It shows low penetrance. 
B)  It exhibits epistasis. 
C)  It exhibits variable expressivity. 
D)  It is a result of heterosis. 
E)  It shows quantitative variation.

Question 20

A cross between two heterozygous parents that differs by two independently assorting traits is a(n) _______ cross.

Accepted Answer

The answer of A cross between two heterozygous parents that...

Exam 12: Inheritance, Genes, and Chromosomes

Which Drosophila individual must be hemizygous?

A test cross of a pea plant with round and yellow seeds yields half round, yellow seeds and half round, green seeds.You conclude that the plant was homozygous for the shape gene and _______ for the color gene.

Refer to the figure showing a family pedigree and recessive inheritance.Note the mother in generation I is a carrier of a rare recessive autosomal trait. What is the probability that a member of generation III will be a carrier of this trait?

A woman has B blood type of the ABO system.Her mother is type O.From this, we can infer that her father

A population of Drosophila simulans carries three alleles at the white locus: the wild-type allele at 86 percent, w1 at 9 percent, and w2 at 5 percent.What can we say about this population?

A(n) _______ cross involves two different unlinked genes, each affecting a different character.

What distinguishes the phenotypes of the different ABO groups?

Nearly all male wasps in natural populations of the species Nasonia vitripenis have small wings.The trait of small wings in this species is thus considered

In cattle, hybrids often are more reproductively fit than the purebreds.Suppose that this increased vigor in hybrids, or heterosis, is due mainly to the lack of inbreeding depression.This would then support the _______ hypothesis.

Consider the F2 progeny of a dihybrid cross.For every double recessive homozygote observed, you should expect _______ double dominant homozygote(s).

The ABO blood groups in humans are determined by a multiple-allele system in which IA and IB are codominant and are both dominant to IO.A newborn infant is type A.The mother is type O.Possible phenotypes of the father are

In humans, which chromosome is inherited only from the mother?

When analyzing Drosophila offspring of test crosses to determine gene linkage, what value for recombination frequency would tell you that two genes are probably not linked?

Wild type fruit flies have red eyes.A white-eyed female fly is crossed with a red-eyed male fly.All of the females from the cross are red-eyed, and all of the males are white-eyed.What type of inheritance pattern is this?

A cross between two heterozygous parents that differs by two independently assorting traits is a(n) _______ cross.

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A population of Drosophila simulans carries three alleles at the white locus: the wild-type allele at 86 percent, w₁ at 9 percent, and w₂ at 5 percent.What can we say about this population?

Consider the F₂ progeny of a dihybrid cross.For every double recessive homozygote observed, you should expect _______ double dominant homozygote(s).

The ABO blood groups in humans are determined by a multiple-allele system in which I^A and I^B are codominant and are both dominant to I^O.A newborn infant is type A.The mother is type O.Possible phenotypes of the father are