Since, both parents are normal and all the sons are affected. Then, Mother would be carrier of the diseased gene and father is normal. Thus, the gene is sex linked recessive. 
NEET UG 2005 — Zoology Principles of Inheritance and Variation
A man and a woman, who do not show any apparent signs of a certain inherited disease, have seven children (2 daughters and 5 sons). Three of the sons suffer from the given disease but none of the daughters affected. Which of the following mode of inheritance do you suggest for this disease?
Held on 30 Apr 2005 · Verified 9 Jul 2026.
sex-linked dominant
sex-linked recessive
sex-limited recessive
autosomal dominant.
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