Hormonal action initiates an expanding cascade of response. It is known as ____

Options

A. Amplification
B. Synergistic effect
C. Antagonistic effect
D. Positive feed back

Answer

### Step-by-Step Solution:

1. **Understanding Hormonal Action**: Hormones act as chemical messengers in the body. They bind to specific receptors on target cells, initiating a series of biochemical responses.

2. **Signaling Pathway**: The binding of a hormone to its receptor triggers a signaling pathway. This pathway involves multiple steps where the signal is relayed and amplified through various molecules.

3. **Cascade of Responses**: When a hormone binds to its receptor, it activates a series of reactions within the cell. Each reaction can activate more molecules, leading to a chain reaction or cascade effect.

4. **Amplification Process**: The term "amplification" refers to the process where a single hormone molecule can trigger a large number of responses. This means that the initial signal is greatly increased, leading to a significant biological effect.

5. **Final Answer**: Therefore, the expanding cascade of responses initiated by hormonal action is known as **Amplification**.