Q. 4 - Biology

Question

X-linked recessive traits in humans (or in Drosophila) are observed ________. 

a. in more males than females 

b. in more females than males

c. in males and females equally 

d. in different distributions depending on the trait 

Step-by-Step Solution

Answer

The correct option is A.

Step. 1 Introduction

X-linked recessive heredity is a method of transferring a genetic characteristic or disease from parent onto offspring via mutations (modifications) in an X chromosome genotype.

Step. 2 Explanation for correct option.

In X-linked recessive transmission, a change inside an X-chromosome gene can cause the trait to be displayed in men, as they have a X and a Y chromosome.

Step. 3 Explanation for incorrect option.

Option b. Males always have a single X and a single Y chromosome, whereas two X chromosomes are present in females. Thus, it is more common in males.

Option c. No, it occurs in males more often.

Option d. No it is not in different distributions depending on the trait, rather depends on the X chromosome.