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General Biology

Study Pack

Set 15 Linkage And Chromosomes

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Question 1

(Multiple Choice)

Free
A man with normal vision who is a dwarf due to achondroplasia has children with a woman who is colorblind and of average height. Dwarfism caused by achondroplasia is autosomal dominant, and red-green color blindness is X-linked recessive. What proportion of their sons are expected to be color blind and of normal height?

A) 0
B) 1/2
C) 1/4
D) all

Answer

Question 2

(Multiple Choice)

Free
Glucose-6-phosphate dehydrogenase deficiency (G6PD) is inherited as an X-linked recessive allele in humans. A woman whose father had G6PD is planning a family with a man who has no history of the disease. What proportion of their sons are expected to have the disease?

A) 100%
B) 1/4
C) 1/2
D) 0

Answer

Question 3

(Multiple Choice)

Free
Which of the following events results in X-inactivation in female mammals?

A) activation of the XIST gene on the X chromosome that will become the Barr body
B) activation of the BARR gene on one X chromosome, which then becomes inactive
C) inactivation of the XIST gene on the X chromosome derived from the male parent
D) attachment of methyl (-CH3) groups to the X chromosome that will remain active

Answer