First generation after a cross is

Options

A. First filial generation
B. `F_(1)` generation
C. Second filial generation
D. Both A and B

Answer

To answer the question regarding the first generation after a cross, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terminology**:
- In genetics, when we perform a cross between two parent organisms, the offspring produced are categorized into different generations.

2. **Identifying the First Generation**:
- The first generation of offspring resulting from a cross between two parent organisms is referred to as the **first filial generation**. This is often abbreviated as **F1 generation**.

3. **Clarifying the Options**:
- The options provided are:
- A) First filial generation
- B) F1 generation
- C) Second filial generation
- D) Both A and B
- Since both A and B refer to the same concept, they are correct.

4. **Understanding Subsequent Generations**:
- The second generation of offspring, which results from the mating of individuals from the F1 generation, is known as the **second filial generation** or **F2 generation**.

5. **Conclusion**:
- Therefore, the answer to the question is that the first generation after a cross is referred to as both the **first filial generation** and the **F1 generation**. The correct option is **D) Both A and B**.

### Final Answer:
The first generation after a cross is both the **first filial generation** and the **F1 generation** (Option D).

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