**Answer:**

**The correct answer is -**

**A) BbTt x bbTt**

**B) .5^4 or 1/16 or 0.0625**

**Explanation:**

As it is given that Brachydactylus and PTC tasters both traits are autosomal dominant conditions which mean only one allele would be enough.

For Branchydactylus and For tasting : man and women will be heterogeneous.

Hence,

The Genotype of man = BbTt

The Genotype of wife = bbTt

b. Answer = 0.0625

For Branchydactylus:

Bb X bb

Possible genotypes:

B b

b Bb( Brachydactylus) bb(normal)

b Bb (Brachydactylus) bb (normal)

The probability of a single child being Branchydactylus = 2/4 = 0.5

So, Probability of all 4 child being Branchydactylus = .5 x .5 x .5 x .5 = 0.0625