Instead of tooth, baleen (hanging horny plates in mouth) are found in

Options

A. Blue whale
B. Shark
C. Dolphin
D. Archaeopteryx

Answer

### Step-by-Step Solution:

1. **Understanding Baleen**: Baleen refers to the filter plates made of keratin that are found in the mouths of certain marine animals. They are used for filtering food from water.

2. **Identifying the Function**: The primary function of baleen is to filter small organisms like krill and plankton from the water, which indicates that it is typically found in aquatic animals.

3. **Composition of Baleen**: Baleen is composed of keratin, the same protein that makes up human hair and nails, and is located in the upper jaw of these animals.

4. **Identifying the Animal**: Baleen is specifically found in baleen whales, which include species like the blue whale. These whales are named for their baleen plates, which resemble bones.

5. **Characteristics of Baleen Whales**: Baleen whales, such as the blue whale, have flippers (modified limbs) that aid in swimming. This adaptation is crucial for their aquatic lifestyle.

6. **Conclusion**: Based on the information, the animal that possesses baleen instead of teeth is the blue whale.

### Final Answer:
Baleen is found in the **blue whale**.

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