Birds and Mammals have `:-`

Options

A. Single and closed type circulation
B. Double and open type cirulation
C. Double and closed type circulation
D. Single and open type cirulation

Answer

**Step-by-Step Solution:**

1. **Understanding Circulatory Systems**: Circulatory systems in animals can be classified into two main types: open and closed. In an open circulatory system, blood is not confined to vessels and flows freely through cavities, while in a closed circulatory system, blood is contained within vessels.

2. **Identifying the Type of Circulation in Birds and Mammals**: Birds and mammals both possess a closed circulatory system. This means that their blood circulates within a network of vessels, ensuring efficient transport of nutrients, gases, and waste.

3. **Differentiating Between Single and Double Circulation**: Circulatory systems can also be categorized based on the number of times blood passes through the heart during one complete cycle.
- **Single Circulation**: Blood passes through the heart only once in a complete circuit. This is typical in fish.
- **Double Circulation**: Blood passes through the heart twice in one complete circuit. This is characteristic of birds and mammals.

4. **Explaining Double Circulation**: In double circulation, blood travels from the heart to the lungs (to get oxygenated) and then back to the heart, before being pumped to the rest of the body. This separation of oxygenated and deoxygenated blood allows for more efficient oxygen delivery to tissues.

5. **Conclusion**: Based on the above points, it is clear that birds and mammals have a double and closed type of circulation.

**Final Answer**: Birds and mammals have double and closed type circulation.

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