Question
Biology Question on Principles of Inheritance and Variation
X-linked recessive gene is
A
Always expressed in males
B
Always expressed in females
C
Lethal
D
Sub-lethal
Answer
Always expressed in males
Explanation
Solution
X-linked recessive characters are expressed only when they are present on X chromosome of male. Recessive characters cannot be expressed over dominant characters. As males have only one X chromosome so if recessive character is present it will always be expressed. There is no other X chromosome in male and Y chromosome does not possess genes which can influence the genes present on X chromosome. Females express X-linked recessive genes only when they are present on both X chromosomes.