Cleavage in arthropods is

Options

A. meroblastic and superficial
B. teloblastic and superficial
C. holoblastic
D. meroblastic and discoidal

Answer

To answer the question about cleavage in arthropods, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Cleavage Types**:
Cleavage refers to the series of rapid cell divisions that occur after fertilization. The types of cleavage include holoblastic, meroblastic, teloblastic, and discoidal.

2. **Analyzing the Options**:
- **Discoidal**: This type of cleavage is characterized by the concentration of yolk at one end of the egg and is typically seen in birds, some reptiles, and certain fishes. It is not found in arthropods. Thus, this option is incorrect.

- **Holoblastic**: This cleavage involves the entire egg being divided into smaller cells and is usually seen in organisms with moderate to sparse yolk, such as certain mammals, flatworms, amphibians, and annelids. However, it is not characteristic of arthropods, making this option also incorrect.

- **Teloblastic**: This type of cleavage is associated with segmented organisms, particularly annelids. It is not applicable to arthropods, so this option is incorrect as well.

- **Meroblastic**: This cleavage involves only a portion of the egg being divided, typically around a central mass of yolk. In arthropods, the cleavage is indeed meroblastic and superficial, where the cleavage furrows do not penetrate the yolk but occur in the cytoplasmic region.

3. **Conclusion**:
Based on the analysis, the correct answer is that cleavage in arthropods is **meroblastic and superficial**.

### Final Answer:
Cleavage in arthropods is **meroblastic and superficial**.

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