A male human is heterozygous for autosomal genes A and B and is also hemizygous for haemophilic gene h. What proportion of his sperms will be abh?

Options

A. `(1)/(8)`
B. `(1)/(32)`
C. `(1)/(16)`
D. `(1)/(4)`

Explanation

To solve the problem, we need to determine the proportion of sperm that will carry the genotype abh from a male who is heterozygous for two autosomal genes (A and B) and hemizygous for the hemophilic gene (h).

### Step-by-Step Solution:

1. **Identify the Genotype of the Male**:
- The male is heterozygous for genes A and B, which means his genotype for these genes is AaBb.
- He is hemizygous for the hemophilic gene h, which means he has one copy of the gene on his X chromosome (X^h) and a Y chromosome (Y).

**Genotype Representation**:
- The complete genotype of the male can be represented as:
- AABb X^h Y

2. **Determine the Possible Gametes**:
- For the genes A and B, since the male is heterozygous (AaBb), he can produce gametes with combinations of these alleles.
- The male can contribute either A or a from gene A and either B or b from gene B.
- For the hemophilic gene, since he has one X chromosome with h and one Y chromosome, he can contribute either X^h or Y.

**Gamete Combinations**:
- The combinations of alleles from A and B can be calculated as follows:
- From A: 2 options (A or a)
- From B: 2 options (B or b)
- From the hemophilic gene: 2 options (X^h or Y)

Thus, the total number of different gametes that can be formed is:
\[ 2 \text{ (from A)} \times 2 \text{ (from B)} \times 2 \text{ (from h)} = 8 \text{ gametes} \]

3. **List the Possible Gametes**:
- The possible combinations of gametes are:
1. ABX^h
2. ABy
3. AbX^h
4. Aby
5. aBX^h
6. aBy
7. abX^h
8. aby

4. **Identify the Gamete of Interest (abh)**:
- We are specifically looking for the gamete that contains the alleles abh.
- From the list of possible gametes, we can see that the gamete "abX^h" corresponds to the genotype abh.

5. **Calculate the Proportion**:
- Out of the 8 possible gametes, only 1 gamete is of the form abh.
- Therefore, the proportion of sperm that will carry the genotype abh is:
\[ \frac{1}{8} \]

### Final Answer:
The proportion of his sperm that will be abh is **1/8**.