A heterozygous father suffers from an autosomal dominant trait. Which of these statements is true ?

Options

A. All sons will suffer from the disease while the daughters will not suffer from the disease
B. All daughters will suffer from the disease while the sone will not suffer from the disease
C. None of his children will suffer from the disease
D. Some of his children may suffer from the disease

Answer

To solve the question regarding the inheritance of an autosomal dominant trait from a heterozygous father, we can follow these steps:

### Step 1: Understand the Genetic Background
- An autosomal dominant trait means that only one copy of the dominant allele is needed for the trait to be expressed.
- A heterozygous father has one dominant allele (A) and one recessive allele (a), represented as Aa.

### Step 2: Determine Possible Gametes
- During gametogenesis, the father can produce two types of gametes: one carrying the dominant allele (A) and one carrying the recessive allele (a).

### Step 3: Consider the Mother's Genotype
- The mother's genotype is not specified in the question. For simplicity, we can assume she is homozygous recessive (aa), which means she does not express the trait.

### Step 4: Create a Punnett Square
- We can set up a Punnett square to determine the possible genotypes of the offspring:

| | A (father) | a (father) |
|------|------------|------------|
| a (mother) | Aa (affected) | aa (not affected) |
| a (mother) | Aa (affected) | aa (not affected) |

### Step 5: Analyze the Results
- The Punnett square shows that there are two possible genotypes for the offspring:
- 50% (Aa) will express the autosomal dominant trait (affected).
- 50% (aa) will not express the trait (not affected).

### Step 6: Conclusion
- Since the father is heterozygous for the autosomal dominant trait, some of his children may suffer from the disease. Therefore, the correct answer is:
- **D. Some of his children may suffer from the disease.**