Question 1

How many Barr bodies are present in an individual with Klinefelter syndrome XXYY)?
A)0
B)1
C)2
D)3
E)4

Accepted Answer

1

Question 2

Which statement is true of sperm?
A)The sperm is larger than the egg.
B)Sperm contains only a Y chromosome.
C)Sperm is not a factor in sex determination.
D)The sperm will contain either an X or a Y chromosome.
E)Sperm is the product of mitosis.

Accepted Answer

The sp erm w ill contai n either an X or a Y chromosome .

Question 3

Assume that you are looking at a case of lethal alleles.Crossing two green corn plants results in 2/3 green progeny and 1/3 white progeny.If you crossed two white progeny with each other,how many of the progeny would you predict to be white?
A)100%
B)75%
C)50%
D)25%
E)0%

Accepted Answer

100%

Question 4

The difference between dominance and epistasis is that
A)dominance masks genes at different loci.
B)epistasis masks genes at the same loci.
C)epistasis masks genes at different loci.
D)all of the above
E)Dominance and epistasis are the same.

Accepted Answer

e pistasis masks genes at diff erent loci .

Question 5

In the ABO blood-type phenotype,which gene is the most epistatic?
A)A
B)B
C)O
D)I
E)H

Accepted Answer

H

Question 6

Assume that connected earlobes are a recessive trait with 73% penetrance.The parents are heterozygous and homozygous recessive for the attached earlobe gene.What is the probability that their first child will have attached earlobes?
A)50%
B)18.75%
C)25%
D)36.5%
E)73%

Accepted Answer

The probability of the child inheriting the recessive allele from both parents is 50%. With 73% penetrance, the probability of expressing the trait is 50% * 73% = 36.5%.

Question 7

What kind of dominance does the following example demonstrate? Individuals with the genotype HH have healthy levels of cholesterol,those with Hh have higher levels of cholesterol,and those with hh have dangerous levels that often lead to heart attacks during childhood.
A)complete dominance
B)incomplete dominance
C)codominance
D)recessive
E)none of the above

Accepted Answer

i ncomplete dominance

Question 8

What is the sexual phenotype of Drosophila that has XXXY sex chromosomes and two sets of autosomes?
A)male
B)female
C)metamale
D)metafemale
E)intersex

Accepted Answer

m etafemale

Question 9

Drosophila melanogaster has been used in genetic studies for over 100 years because of its many useful characteristics.Which of the following is NOT one of these characteristics?
A)produces many progeny female lays 400-500 eggs)
B)easy to identify phenotypes
C)easy to culture in laboratory
D)has a generation time similar to that of humans
E)small size

Accepted Answer

h as a generation time similar to that of humans

Question 10

A child who is blood type A has a mother who is blood type B.In a paternity suit a man is accused of being the father.He has blood type AB.Is he the father?
A)yes
B)no
C)He cannot be excluded as the father.
D)There is a 12.5% chance that he is the father.

Accepted Answer

He cannot be excluded as the father.

Question 11

Sex-influenced traits are encoded by ________ genes and sex-linked traits are encoded by _______ genes.
A)sex-chromosome; autosomal
B)autosomal; sex-chromosome
C)autosomal; autosomal
D)sex-chromosome; sex-chromosome
E)none of the above

Accepted Answer

autosomal; sex - chromosome

Question 12

When studying Arabidopsis a researcher isolates a gene mutation that produces a shorter stem-height phenotype.Interestingly,when this gene is present wild-type plantand the seedling is germinated at the lower temperature of 12$\degree$C,the same short-stem phenotype is replicated.This phenomenon is known as
A)epistasis
B)anticipation
C)phenocopy
D)genomic imprinting
E)continuous characteristics

Accepted Answer

phenocopy

Question 13

While studying a new human disease you discover that the disease is linked to a mitochondrial gene.You can be reasonably sure that the disease is inherited _____________________.
A)from mother to child
B)from father to child
C)by both mother and father
D)from either mother or father

Accepted Answer

f rom mother to child

Question 14

When Morgan crossed a red-eyed female with a white-eyed male,which results made Morgan think that the locus affecting eye color was on the X chromosome?
A)All F1 male and female flies had red eyes.
B)All F1 male and female flies had white eyes.
C)In the F2,all females had red eyes,and half of the males had red eyes and the other half had white eyes.
D)In the F2,half of males and females had red eyes and the other half had white eyes.
E)F2 generations were sterile.

Accepted Answer

In the F2,all females had red eyes,and half of the males had red eyes and the other half had white eyes.

Question 15

In various crosses examining three different Drosophila traits,you find the following ratios: 9:3:4,9:7,and 12:3:1.What kind of epistasis is each?
A)recessive epistasis,dominant epistasis,duplicate recessive epistasis
B)dominant epistasis,duplicate recessive epistasis,recessive epistasis
C)recessive epistasis,duplicate recessive epistasis,dominant epistasis
D)duplicate recessive epistasis,dominant epistasis,recessive epistasis
E)dominant epistasis,recessive epistasis,duplicate recessive epistasis

Accepted Answer

recessive epistasis, duplicate recessive epistasis,dominant epistasis

Question 16

Males and females express the same amount of X-chromosome genes despite the fact that females have more X chromosomes.Animals approach this problem in different ways.Which of the following is an example?
A)Female Caenorhabditis elegans express X-chromosome genes at 50%.
B)Male fruit flies double the expression of their X-chromosome genes.
C)Female humans inactivate one of their X chromosomes.
D)all of the above
E)none of the above

Accepted Answer

Female humans inactivate one of their X chromoso mes.

Question 17

What is true about sexual reproduction?
A)Each parent contributes a haploid gene set to offspring.
B)Sexual reproduction consists of mitosis only.
C)Sexual reproduction involves the union of diploid gametes.
D)Sexual reproduction produces a haploid zygote.
E)all of the above

Accepted Answer

Each parent contributes a haploid gene set to offspring .

Question 18

A human with an XY chromosome pair appears female.What might explain this person's condition?
A)This person suffers from Turner syndrome.
B)This person suffers from Klinefelter syndrome.
C)This person has a mutated SRY gene.
D)This person has an extra copy of the SRY gene.
E)The XY determination was an error because it is impossible for a human XY individual to be female.

Accepted Answer

This person has a mutated SRY g ene.

Question 19

If a color-blind female has children,what do we know about all of her sons?
A)Half of the sons will be color-blind.
B)All sons will be color-blind.
C)All sons will have normal color vision.
D)She would not be able to have a son.
E)It is impossible to know without knowing the father's genotype.

Accepted Answer

All sons will be color - blind .

Question 20

Yeast mitochondria have a tubular morphology.In a mutagenic screen,two mutants are isolated that have fragmented mitochondria instead of tubular mitochondria.To determine if these two mutations are at the same or different loci,the two mutants are crossed.The progeny all have tubular mitochondria.What do you conclude?
A)The mutations are at different loci.
B)The mutations are at the same locus.
C)Not enough data is presented.

Accepted Answer

The m utations are at different loci .

Quiz 4: Extensions and Modifications of Basic Principles

How many Barr bodies are present in an individual with Klinefelter syndrome XXYY) ?

Which statement is true of sperm?

Assume that you are looking at a case of lethal alleles.Crossing two green corn plants results in 2/3 green progeny and 1/3 white progeny.If you crossed two white progeny with each other,how many of the progeny would you predict to be white?

The difference between dominance and epistasis is that

In the ABO blood-type phenotype,which gene is the most epistatic?

Assume that connected earlobes are a recessive trait with 73% penetrance.The parents are heterozygous and homozygous recessive for the attached earlobe gene.What is the probability that their first child will have attached earlobes?

What kind of dominance does the following example demonstrate? Individuals with the genotype HH have healthy levels of cholesterol,those with Hh have higher levels of cholesterol,and those with hh have dangerous levels that often lead to heart attacks during childhood.

What is the sexual phenotype of Drosophila that has XXXY sex chromosomes and two sets of autosomes?

Drosophila melanogaster has been used in genetic studies for over 100 years because of its many useful characteristics.Which of the following is NOT one of these characteristics?

A child who is blood type A has a mother who is blood type B.In a paternity suit a man is accused of being the father.He has blood type AB.Is he the father?

Sex-influenced traits are encoded by __ genes and sex-linked traits are encoded by _ genes.

While studying a new human disease you discover that the disease is linked to a mitochondrial gene.You can be reasonably sure that the disease is inherited _____________________.

When Morgan crossed a red-eyed female with a white-eyed male,which results made Morgan think that the locus affecting eye color was on the X chromosome?

In various crosses examining three different Drosophila traits,you find the following ratios: 9:3:4,9:7,and 12:3:1.What kind of epistasis is each?

Males and females express the same amount of X-chromosome genes despite the fact that females have more X chromosomes.Animals approach this problem in different ways.Which of the following is an example?

What is true about sexual reproduction?

A human with an XY chromosome pair appears female.What might explain this person's condition?

If a color-blind female has children,what do we know about all of her sons?