XX-XO sex chromosome complement occurs in

Options

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

Answer

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

### Step-by-Step Solution:

1. **Understanding Sex Chromosome Systems**:
- In various organisms, sex is determined by different chromosomal systems. The XX-XY and XX-XO systems are two common types.

2. **Identifying the XX-XO System**:
- In the XX-XO system, females have two X chromosomes (XX), while males have one X chromosome and no second sex chromosome (XO). This means that males do not have a Y chromosome.

3. **Gamete Production**:
- Females (XX) produce gametes that contain one X chromosome each. Therefore, all female gametes are the same (homo gametes).
- Males (XO) produce two types of gametes: one with an X chromosome (X) and one without any sex chromosome (O).

4. **Example of Organisms with XX-XO System**:
- This system is commonly found in certain insects. A well-known example of an organism that exhibits the XX-XO sex determination system is the cockroach.

5. **Conclusion**:
- Therefore, the XX-XO sex chromosome complement occurs in cockroaches, which belong to the class Insecta in the phylum Arthropoda.

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

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