Pheromone is

Options

A. Product of endocrine gland
B. A protein
C. mRNA
D. Used for animal communication

Answer

**Step-by-Step Text Solution:**

1. **Understanding Pheromones:**
- Pheromones are chemical substances that are secreted or excreted by an organism.
- They play a crucial role in communication among members of the same species.

2. **Options Analysis:**
- The question provides several options:
a. Product of endocrine gland
b. A protein
c. Messenger RNA
d. Used for animal communication

3. **Evaluating Each Option:**
- **Option a:** Pheromones are not produced by endocrine glands like hormones; instead, they are released into the environment.
- **Option b:** Pheromones are not proteins; they are typically small organic molecules.
- **Option c:** Pheromones are not messenger RNAs; they are chemical signals, not genetic material.
- **Option d:** This option is correct. Pheromones are indeed used for animal communication, triggering social responses among individuals of the same species.

4. **Examples of Pheromones:**
- Simple pheromones like isomyl acetate in bees and valeric acid are examples of how these compounds can vary in complexity.
- Some pheromones can be complex molecules related to steroids.

5. **Conclusion:**
- The correct answer to the question "Pheromone is" is that it is "used for animal communication."

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