Close type circulatory system is present in which phylum?

Answer

To determine which phylum has a closed type of circulatory system, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Types of Circulatory Systems**:
- There are two main types of circulatory systems: open and closed.
- In an open circulatory system, blood flows freely into large spaces called sinuses.
- In a closed circulatory system, blood is contained within blood vessels (arteries, veins, and capillaries).

2. **Identify Organisms with Closed Circulatory Systems**:
- Closed circulatory systems are more efficient for transporting nutrients and oxygen.
- This system is primarily found in vertebrates, which include mammals, birds, reptiles, amphibians, and fish.

3. **Consider Invertebrates with Closed Circulatory Systems**:
- Some invertebrates also possess a closed circulatory system.
- A notable example is the phylum Annelida, which includes earthworms and leeches.

4. **Conclude the Answer**:
- The closed type of circulatory system is present in the phylum **Chordata** (which includes all vertebrates) and the phylum **Annelida** (some invertebrates).

### Final Answer:
The closed type of circulatory system is present in the phyla **Chordata** and **Annelida**.

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