Which of the following is an incorrect statement?

Options

A. Hormones are required in trace amounts
B. Hormones are intra-cellular messengers
C. Hormones are secreted by endocrine glandular cells
D. Hormones are secreted in response to a particular stimulus

Answer

To determine which statement is incorrect regarding hormones, we will analyze each option provided in the question step by step.

### Step-by-Step Solution:

1. **Understanding the Role of Hormones**:
- Hormones are chemical messengers that are secreted into the bloodstream and travel to target organs to elicit specific physiological responses.

2. **Analyzing the First Statement**:
- **Statement**: "Hormones are required in trace amount."
- **Evaluation**: This statement is correct. Hormones are indeed produced and required in very small amounts to regulate various bodily functions.

3. **Analyzing the Second Statement**:
- **Statement**: "Hormones are intracellular messengers."
- **Evaluation**: This statement is incorrect. Hormones are not classified as intracellular messengers; they are typically considered intercellular messengers, as they transmit signals between different cells.

4. **Analyzing the Third Statement**:
- **Statement**: "Hormones are secreted by endocrine glands."
- **Evaluation**: This statement is correct. Endocrine glands are responsible for the secretion of hormones directly into the bloodstream.

5. **Analyzing the Fourth Statement**:
- **Statement**: "Hormones are secreted in response to a particular stimulus."
- **Evaluation**: This statement is also correct. Hormones are released in response to specific stimuli, which can be physiological changes or signals from other hormones.

6. **Conclusion**:
- After evaluating all statements, the incorrect statement is the second one: "Hormones are intracellular messengers."

### Final Answer:
The incorrect statement is: **"Hormones are intracellular messengers."**

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