Which of the following features is not present in Periplaneta americana?

Options

A. Indeterminate and radial cleavage dur-
ing embryonic development
B. Exoskeleton composed of N-acetylgiu-
cosamine
C. Metamerically segmented body
D. Schizocoelom as body cavity

Answer

To determine which feature is not present in Periplaneta americana (the American cockroach), we will analyze the characteristics of this organism step by step.

### Step-by-Step Solution:

1. **Identify the Organism**:
- Periplaneta americana is the scientific name for the American cockroach. Understanding its classification helps us know its biological features.

2. **Understand the Body Structure**:
- The body of the cockroach is divided into three main parts: the head, thorax, and abdomen. This is a typical feature of insects.

3. **Examine Internal Segmentation**:
- Internally, the cockroach exhibits segmentation. Although it appears to have three main sections externally, it is segmented internally, which is a characteristic of many arthropods.

4. **Check the Composition of the Exoskeleton**:
- The exoskeleton of the cockroach is made of chitin, specifically composed of N-acetylglucosamine. This is a true statement regarding its structure.

5. **Investigate Embryonic Development**:
- The embryonic development of Periplaneta americana is characterized by spiral and determinate cleavage. This is different from indeterminate and radial cleavage, which is not a feature of cockroaches.

6. **Assess Body Cavity Type**:
- The body cavity of the cockroach is of the schizocoelom type, meaning that the coelom (body cavity) develops through the splitting of mesodermal tissue, which is a true statement.

7. **Conclusion**:
- The feature that is not present in Periplaneta americana is the embryonic development characterized by indeterminate and radial cleavage. Instead, it has spiral and determinate cleavage.

### Final Answer:
The feature that is not present in Periplaneta americana is **indeterminate and radial cleavage during embryonic development**.