In most of the higher unisexual animals there is one chromosomal pair which isn not indentical in two sexes ,These are called

Options

A. Non homologous chromosomes
B. Non identical chromossomes
C. Non compatible chromosomes
D. Sex chromosomes

Answer

To solve the question, we need to identify the type of chromosomes that are not identical in two sexes in higher unisexual animals. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Terminology
- **Unisexual Animals**: These are animals that have distinct male and female individuals, meaning that each individual possesses only one type of sex (either male or female).

### Step 2: Identify Chromosome Types
- In higher unisexual animals, chromosomes can be categorized into two types:
1. **Autosomes**: These are chromosomes that are identical in both sexes. They carry genes that are not related to sex determination.
2. **Sex Chromosomes**: These are the chromosomes that determine the sex of an individual. They are not identical in males and females.

### Step 3: Focus on the Question
- The question specifically asks for the chromosomal pair that is not identical in two sexes.

### Step 4: Analyze the Options
- **Option 1: Non-homologous chromosome**: This term is not commonly used in this context.
- **Option 2: Non-identical chromosome**: This is a vague term and does not specifically refer to sex determination.
- **Option 3: Non-compatible chromosome**: This term does not apply to the context of sex determination.
- **Option 4: Sex chromosome**: This is the correct term as it refers to chromosomes that differ between males and females (e.g., XY in males and XX in females).

### Step 5: Conclusion
- The correct answer to the question is **Option 4: Sex Chromosome**.

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