The sex-determination mechanisms based onfemale.heterogamety are:

Options

A. ZZ-ZW type
B. ZZ-ZO type
C. Both (a) and (b)
D. Neither (a) nor (b)

Explanation

To solve the question regarding the sex-determination mechanisms based on female heterogamety, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Female Heterogamety**:
- Female heterogamety refers to a situation where females produce two different types of gametes (heterogametic), while males produce one type (homogametic). In this case, females have two different sex chromosomes.

2. **Identifying the Types of Sex Determination**:
- The question provides two types of sex determination mechanisms: ZZWZ and ZZO.
- **ZZZW Type**: In this system, males are homogametic (ZZ) and females are heterogametic (ZW). This type is commonly seen in birds.
- **ZZO Type**: Here, males are again homogametic (ZZ) and females are heterogametic (ZO). This type is observed in certain insects, such as butterflies and moths.

3. **Analyzing the Options**:
- **Option A (ZZZW Type)**: This option represents a mechanism where females are heterogametic (ZW), which is correct.
- **Option B (ZZO Type)**: This option also represents a mechanism where females are heterogametic (ZO), which is also correct.
- **Both A and B**: Since both types of mechanisms are based on female heterogamety, this option is correct.
- **Neither A nor B**: This option is incorrect since both A and B are valid mechanisms.

4. **Conclusion**:
- Since both the ZZWZ and ZZO types are mechanisms of sex determination based on female heterogamety, the correct answer is **both A and B**, which corresponds to option C.

### Final Answer:
The sex-determination mechanisms based on female heterogamety are: **both A and B (Option C)**.

---