In Melandrium sex determination is of

Options

A. XX-XO
B. ZZ-ZW
C. XX-XY
D. XY-XO

Answer

### Step-by-Step Solution:

1. **Understanding Melandrium**: Melandrium is a genus of flowering plants that belong to the Caryophyllaceae family. It is important to know the biological classification to understand its reproductive mechanisms.

2. **Sex Determination Mechanism**: In Melandrium, sex determination follows the XX-XY system. This means that the females are typically XX and the males are XY, similar to the sex determination system in humans.

3. **Analyzing the Options**: The question provides several options for sex determination systems:
- **Option 1**: XXS and XO - This is not applicable to Melandrium; it is related to other organisms.
- **Option 2**: ZZ and ZW - This is a system found in some animals, particularly birds, and does not apply to Melandrium.
- **Option 3**: XS and XY - This is the correct option as it directly corresponds to the sex determination in Melandrium.
- **Option 4**: XY and XO - This is another system found in some animals and does not apply to Melandrium.
- **Option 5**: XX and XW - This is also related to birds and does not apply to Melandrium.

4. **Conclusion**: After analyzing the options, the correct answer for the sex determination in Melandrium is **XX and XY**.

### Final Answer:
In Melandrium, sex determination is of **XX and XY**.