Biology revival

Biology Level 1

In a cross between a normal man and a haemophiliac carrier woman, what is the probability in % that the offspring is haemophiliac?

100\%

25\%

75\%

50\%

2 solutions

Satyabrata Dash
Jun 3, 2018

haemophilia is an x-linked recessive disorder

MAN - $XY$

FEMALE - $X^CX$

OFFSPRINGS -

$X^CX$ (CARRIER FEMALE)

$X^CY$ (AFFECTED MALE)

$XX$ (NORMAL)

$XY$ ( NORMAL)

Thus, $\frac{1}{4}$ offsprings affected = $25 \%$ %

Ashish Menon
Apr 23, 2016

The answer can be obtained by drawing a punnette square. $50\%$ are normal, $25\%$ are carrier and $\boxed{25\%}$ are affected.

Morw information:- The affected offspring is a male child whose X chromosome is affected.