Blood pumped by the heart passes into sinuses in

Options

A. Fishes
B. Earthworms
C. Insects
D. Birds

Answer

To solve the question "Blood pumped by the heart passes into sinuses in which organism?", we will follow these steps:

### Step 1: Understand the circulatory systems
- There are two main types of circulatory systems: open and closed.
- In a closed circulatory system, blood is contained within blood vessels.
- In an open circulatory system, blood (or hemolymph) is not confined to blood vessels and instead flows freely in cavities called sinuses.

### Step 2: Identify the organisms mentioned
- The question provides several options, including fishes, earthworms, and insects (specifically cockroaches).
- Fishes and earthworms are known to have closed circulatory systems.
- Insects, such as cockroaches, have an open circulatory system.

### Step 3: Analyze the circulatory system of cockroaches
- In cockroaches, the heart pumps blood into sinuses, which are open spaces in the body.
- The blood in these sinuses is referred to as hemolymph, and it bathes the organs directly.

### Step 4: Determine the correct answer
- Since the question specifically asks about blood passing into sinuses, the correct answer is the organism with an open circulatory system, which is the cockroach (insect).
- Therefore, the correct option is "insects" (option 3).

### Final Answer:
Blood pumped by the heart passes into sinuses in insects, specifically in cockroaches.

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