Question

citruscollege. E. C LUJ Question 26 Icthyosis, which causes scaly skin, is an X-linked recessive trait. A woman who has icthyosis has a daughter with a normal man. What is the probability that she has the disorder? Question 27 What would be the consequence it human females did NOT have X-inactivation? Males would have lower levels of expression of all penes on the chromosome Females would have lower levels of expression of all genes on the X chromosome Males would have higher levels of expression of all genes on the X chromosome Female would have higher levels of expression of all genes on the x chromosome Question 28

Answer 1

Ans.26. Option B is the correct answer.

EXPLANATIONS:- The X linked recessive disease are always most probably occurs in the males as only one X chromosome with recessive trait is required in males for expression of the trait. But in case of the female, the trait should be present on both the X chromosome, so they are most carrier. So no female will be Ichthyosis. All females will be carrier but all Male will be diseased. So probability is zero percent.

Ans. 27. Option D is the correct answer.

EXPLANATIONS:- If there would be no inactivation of the X chromosome in female , there will be a more expression of the X linked gene in the females.