The rule of probability is useful in calculating the risk that certain individuals will inherit a particular genotype.

Options

A. product
B. summation
C. additive
D. none of the above is correct

Answer

To solve the problem regarding the use of the rule of probability in calculating the risk of inheriting a particular genotype, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Probability in Genetics**:
- In genetics, the probability of inheriting a specific genotype can be calculated using the rules of probability. This is crucial when predicting the likelihood of offspring inheriting certain traits from their parents.

2. **Identifying Genotype Probabilities**:
- Let's denote the probability of inheriting a particular allele (gene variant) as 'x' for one parent and 'y' for the other parent. For example, if one parent has a genotype that gives a 50% chance (1/2) of passing on a certain allele, and the other parent has a genotype that gives a 25% chance (1/4), we can represent these probabilities as:
- Parent 1: Probability (x) = 1/2
- Parent 2: Probability (y) = 1/4

3. **Calculating Combined Probability**:
- To find the probability of inheriting a specific combination of alleles from both parents, we multiply the individual probabilities:
- Combined Probability = x * y
- In our example, Combined Probability = (1/2) * (1/4) = 1/8.

4. **Understanding Additive Effects**:
- It’s important to note that the additive effect of probabilities does not apply here. Instead, we use the product rule for independent events in genetics. This means that the probabilities do not simply add up; they are multiplied.

5. **Summarizing the Results**:
- If we were to calculate the total probability of inheriting a particular genotype based on multiple alleles or combinations, we would continue to use the product of the individual probabilities for each allele involved.

6. **Final Probability Calculation**:
- If we have multiple combinations, we can sum the probabilities of each successful combination to find the total probability of inheriting a desired genotype.