Question
Biology Question on Principles of Inheritance and Variation
If a genetic disease is transferred from a phenotypically normal but carrier female to only some of the male progeny, the disease is
A
autosomal dominant
B
autosomal recessive
C
sex-linked dominant
D
sex-linked recessive
Answer
sex-linked recessive
Explanation
Solution
The sex linked recessive disease shows its transmission from unaffected carrier female to some of the male progeny e.g., haemophilia. The heterozyous female (carrier) of haemophilia may transmit the disease to sons. The possibility of a female becoming a haemophilic is extremely rare because mother of such a female has to be at least carrier and the father should be haemophilic.