Question 1

Duchenne muscular dystrophy is a serious condition caused by a recessive allele of a gene on the human X chromosome. The patients have muscles that weaken over time because they have absent or decreased dystrophin, a muscle protein. They rarely live past their 20s. How likely is it for a woman to have this condition?

Accepted Answer

A)   Women can never have this condition.
B)   One-half of the daughters of an affected man would have this condition.
C)   One-fourth of the daughters of an affected father and a carrier mother could have this condition.
D)   Very rarely: it is rare that an affected male would mate with a carrier female.
E)   Only if a woman is XXX could she have this condition.F) None of the above
G) C) and D)

Question 2

In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black female and an orange male?

Accepted Answer

A)   tortoiseshell females; tortoiseshell males
B)   black females; orange males
C)   orange females; orange males
D)   tortoiseshell females; black males
E)   orange females; black malesF) A) and B)
G) A) and C)

Question 3

Please use the following information to answer the question(s)  below.
A plantlike organism on the planet Pandora can have three recessive genetic traits: bluish leaves, due to an allele (a)  of gene A; a feathered stem, due to an allele (b)  of gene B; and hollow roots due to an allele (c)  of gene C. The three genes are linked and recombine.
A geneticist did a testcross with an organism that had been found to be heterozygous for the three recessive traits and was able to identify progeny of the phenotypic distribution (+ = wild type)  shown in Figure 12.3.  Figure 12.3
-In which progeny phenotypes has there been recombination between genes A and B?

Accepted Answer

A)   1, 2, 5, and 6
B)   1, 3, 6, and 7
C)   2, 4, 5, and 8
D)   2, 3, 5, and 7
E)   in all 8 of themF) D) and E)
G) A) and C)

Question 4

Which of the following statements correctly describes linkage?

Accepted Answer

A)   The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them.
B)   The observed frequency of recombination of two genes that are far apart from each other has a maximum value of 100%.
C)   All of the traits that Mendel studied-seed color, pod shape, flower color, and others-are due to genes linked on the same chromosome.
D)   Linked genes are found on different chromosomes.E) A) and D)
F) B) and C)

Question 5

Which of the following is known as a Philadelphia chromosome?

Accepted Answer

A)   a human chromosome 22 that has had a specific translocation
B)   a human chromosome 9 that is found only in one type of cancer
C)   an animal chromosome found primarily in the mid-Atlantic area of the United States
D)   an imprinted chromosome that always comes from the motherE) None of the above
F) B) and C)

Question 6

When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result?

Accepted Answer

A)   The gene involved is on the Y chromosome.
B)   The gene involved is on the X chromosome.
C)   The gene involved is on an autosome, but only in males.
D)   Eye color in flies is a multifactorial trait.E) None of the above
F) All of the above

Exam 12: The Chromosomal Basis of Inheritance

When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result?

Correct Answer
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Which of the following is known as a Philadelphia chromosome?

Correct Answer
verified

Which of the following statements correctly describes linkage?

Correct Answer
verified

Correct Answer
verified

In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black female and an orange male?

Correct Answer
verified

Correct Answer
verified

Exam 12: The Chromosomal Basis of Inheritance

When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result?

Correct AnswerverifiedShow Answer

Which of the following is known as a Philadelphia chromosome?

Correct AnswerverifiedShow Answer

Which of the following statements correctly describes linkage?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black female and an orange male?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified