Fertilized eggs of Periplaneta americana are encased in

Options

A. Ootheca
B. Cocoon
C. Genital chamber
D. Phallomere

Explanation

To answer the question "Fertilized eggs of Periplaneta americana are encased in," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Organism**: Periplaneta americana is the scientific name for the American cockroach. Knowing the basic biology of this organism is essential.

2. **Identify the Female Reproductive Structure**: In female cockroaches, there is a specific structure involved in the reproduction process. This includes parts like the genital pouch, which is crucial for egg development.

3. **Know the Terms**: The key term related to the encasement of fertilized eggs in cockroaches is "ootheca." This is a special casing that protects the eggs.

4. **Clarify the Role of Ootheca**: The ootheca is produced by the female cockroach and contains the fertilized eggs. It is designed to protect the eggs until they hatch.

5. **Count the Eggs**: Female cockroaches can produce multiple oothecae, typically around 9 to 10, and each ootheca can contain 14 to 16 eggs.

6. **Conclusion**: Based on the above information, the correct answer to the question is that fertilized eggs of Periplaneta americana are encased in an "ootheca."

### Final Answer:
Fertilized eggs of Periplaneta americana are encased in an **ootheca**.

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