XX-XO sex chromosome complement occurs in

Options

A. Cockroach
B. Honey bee
C. Human beings
D. Chimpanzee

Answer

To solve the question regarding the XX-XO sex chromosome complement, we will follow these steps:

### Step-by-Step Solution:

1. **Understanding the XX-XO System**:
- In the XX-XO sex determination system, females have two X chromosomes (XX), while males have only one X chromosome (XO). The "O" denotes the absence of a second sex chromosome.

2. **Identifying Organisms with XX-XO System**:
- This chromosomal complement is commonly found in certain insects. One of the most notable examples is cockroaches.

3. **Comparing with Other Systems**:
- It is important to differentiate this system from others:
- In honey bees, a haplodiploid system is present where males are haploid (having one set of chromosomes) and females are diploid (having two sets).
- Humans and chimpanzees have an XY sex-determination system, where males have one X and one Y chromosome.

4. **Conclusion**:
- Based on the understanding of the XX-XO system and the examples provided, we can conclude that the XX-XO sex chromosome complement occurs in cockroaches.

### Final Answer:
The XX-XO sex chromosome complement occurs in **cockroaches**.

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