Chemicals synthesised by one organism that affect behaviour of another member of the same species are called

Options

A. Enzymes
B. Hormones
C. Flavoids
D. Pheromones.

Answer

To solve the question, "Chemicals synthesised by one organism that affect the behaviour of another member of the same species are called," we will analyze the options provided:

1. **Enzymes**:
- Enzymes are biological catalysts that speed up chemical reactions in the body. They are not involved in communication between organisms of the same species. Therefore, this option is incorrect.

2. **Hormones**:
- Hormones are chemical messengers produced by endocrine glands and released into the bloodstream to regulate various functions in the body. While they affect behavior, they primarily act within the same organism rather than between different individuals of the same species. Thus, this option is also incorrect.

3. **Flavonoids**:
- Flavonoids are a class of plant metabolites that provide various health benefits and are not specifically involved in communication between members of the same species. Therefore, this option is incorrect as well.

4. **Pheromones**:
- Pheromones are chemicals secreted by an organism that influence the behavior of other members of the same species. They are often used for communication, such as attracting mates or signaling danger. This option fits the definition given in the question.

Based on the analysis, the correct answer is **pheromones**.

**Final Answer**: Pheromones

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