Select the correct option with respect to characteristic. Features of given animals :
(A) Annelida : Metamerically segmented and schizocoelomate animals.
(b ) Arthropoda : joined appendages with a closed circulatory system.
(C) Ctenophora: shown bioluminescence and also known as sea walnuts.
(d) porifera : Archaeocytes are called collar cells. lines the spongocoel .

Options

A. (a) , (b) , (c) are correct.
B. (a) , (c) , (d) are correct
C. (b) and (d) are incorrect
D. only (d) is incorrect

Answer

To solve the question regarding the characteristics of the given animal phyla, we will analyze each option step by step:

### Step 1: Analyze Annelida
- **Characteristic Given**: Metamerically segmented and schizocoelomate animals.
- **Explanation**: Annelids are indeed metamerically segmented, meaning their bodies are divided into segments both externally and internally. They are also schizocoelomate, which means their coelom (body cavity) is formed by the splitting of the mesoderm.
- **Conclusion**: This statement is **correct**.

### Step 2: Analyze Arthropoda
- **Characteristic Given**: Jointed appendages with a closed circulatory system.
- **Explanation**: Arthropods do have jointed appendages, which is a defining feature. However, they possess an open circulatory system, not a closed one. In an open circulatory system, blood is not confined to vessels but bathes the organs directly.
- **Conclusion**: This statement is **incorrect**.

### Step 3: Analyze Ctenophora
- **Characteristic Given**: Show bioluminescence and are also known as sea walnuts.
- **Explanation**: Ctenophores are known for their ability to exhibit bioluminescence and are commonly referred to as sea walnuts or comb jellies. They have eight comb-like structures called ctenes.
- **Conclusion**: This statement is **correct**.

### Step 4: Analyze Porifera
- **Characteristic Given**: Archaeocytes are called collar cells and line the spongocoel.
- **Explanation**: This statement is incorrect. The collar cells are actually called choanocytes, not archaeocytes. Choanocytes line the spongocoel and are responsible for filtering food from the water.
- **Conclusion**: This statement is **incorrect**.

### Final Evaluation of Options:
- **Option A**: A, B, and C are correct. (Incorrect, as B is wrong)
- **Option B**: A, C, and D are correct. (Incorrect, as D is wrong)
- **Option C**: B and D are correct. (Incorrect, as both B and D are wrong)
- **Option D**: A and C are correct. (Correct, as both A and C are correct)

### Final Answer:
The correct option is **D: A and C are correct**.

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