# A man who is heterozygous for the disease Haemophilia…

Posted by: 516 views

Latest posts by Admin (see all)

### The New Fashion Pyramid: Part 1/2

The New Fashion Pyramid: Part 1/2
QuizTablet Videos

A. 0%

B. 25%

C. 50%

D. 75%

C

## DETAILS…

Let A = the dominant normal allele,

And a = the recessive faulty allele.

The man’s heterozygous gene will be = Aa

And the woman’s double recessive gene will be = aa

Solving for the possible offspring, we have:

Aa + aa   =    A(aa) + a(aa)  =  (Aa  +  Aa)  + (aa  +  aa)  =  2Aa + 2aa

RELATED!  Which of the following results from the cross between Yy and Yy...

Now, out of the four offspring, two will be heterozygous (unlikely to have the disease), and two will be double recessive (sure to have the disease). This means the percentage of offspring likely to have the disease will be: (2/4) X 100 = 50%

### Now to the right option…

1. Option A is incorrect; certainly not zero percent.
2. Option B is also incorrect; not 25% or one-fourth.
3. Yes, 50% according to our calculations, C is correct.
4. Actually, D is incorrect; not 75% or three-fourth.