When a hybrid produces sterlie or infertile offspring , it is known as

Options

A. A.Hybrid sterility
B. B.Hybrid breakdown
C. C.Hybrid inviability
D. D.Gametic isolation

Answer

To solve the question "When a hybrid produces sterile or infertile offspring, it is known as", we will analyze the options provided and determine the correct answer step by step.

### Step 1: Understand the Question
The question is asking for a term that describes the phenomenon where a hybrid (the offspring of two different species) is unable to produce viable offspring. This can occur in various contexts in biology, particularly in the study of speciation and reproductive barriers.

**Hint:** Focus on the definitions of the terms related to hybridization and reproductive barriers.

### Step 2: Analyze the Options
1. **Hybrid Sterility**: This term refers to a situation where the hybrid offspring are sterile or infertile, meaning they cannot reproduce. This is often observed in the first generation (F1) of hybrids.

2. **Hybrid Breakdown**: This occurs when the first generation of hybrids (F1) is fertile, but when they breed, their offspring (F2) are sterile or have reduced fitness. This is a post-zygotic barrier.

3. **Hybrid Inviability**: This term describes a situation where the hybrid offspring do not survive to maturity. This is also a post-zygotic barrier but focuses on the inability of the hybrid to develop into a healthy adult.

4. **Gametic Isolation**: This is a prezygotic barrier where the gametes (sperm and egg) of two different species do not fuse to form a zygote, preventing fertilization.

**Hint:** Compare the definitions of each term to identify which one specifically refers to sterility in hybrids.

### Step 3: Identify the Correct Answer
From the analysis of the options:
- **Hybrid Sterility** is the correct answer because it directly refers to hybrids that are sterile or infertile, which is exactly what the question is asking.

### Conclusion
The correct answer to the question "When a hybrid produces sterile or infertile offspring, it is known as" is **Hybrid Sterility**.

**Final Answer:** Hybrid Sterility