Question

Choose the group of correct statements regarding sex-linked inheritance.
A) Y-linked genes are inherited only in males.
B) X-linked genes are inherited only in females.
C) Colourblindness shows criss-cross inheritance.
D) Haemophilia is Y-linked recessive disorder.
E) The frequency of colourblind women is much less than colourblind men.

• A. A, D and E only
• B. B and D only
• C. A, C and E only
• D. B, D and E only

Hint:

Judge each statement separately: Y-linked genes, X-linked genes, criss-cross inheritance, haemophilia and colour-blindness frequency.

Answer 1

The Correct Option is C

Step 1: Statement A
Y-linked (holandric) genes lie only on the Y chromosome, so they pass from father to son and appear only in males. True.

Step 2: Statements B and D
X-linked genes are present in both males and females, so B is false. Haemophilia is an X-linked recessive disorder, not Y-linked, so D is false.

Step 3: Statements C and E
Colour blindness passes from an affected man through a carrier daughter to her son, which is criss-cross inheritance. True.
A woman needs two recessive alleles to be colour blind, while a man needs only one, so colour-blind women are far fewer. True.

Step 4: Combine
The true statements are A, C and E.

Final Answer:
Statements A, C and E are correct. \[ \boxed{\text{(C) }\text{A, C and E only}} \]