In living organisms, the chemicals/biomolecules are constantly being made and changed from one form to the another Such activity is

Options

A. Metabolism
B. Catabolism
C. Reproduction
D. Irritability

Explanation

To solve the question regarding the constant making and changing of chemicals or biomolecules in living organisms, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks about the activity in living organisms where chemicals or biomolecules are constantly made and changed from one form to another.

2. **Analyze the Options**:
- **Option A: Metabolism**: This refers to the sum total of all biochemical reactions occurring in an organism, including both the building up (anabolism) and breaking down (catabolism) of substances.
- **Option B: Catabolism**: This is a part of metabolism that specifically involves the breakdown of biomolecules into simpler forms, such as during digestion.
- **Option C: Reproduction**: This is the process by which organisms produce new individuals, which does not directly relate to the constant transformation of biomolecules.
- **Option D: Irritability**: This refers to the ability of an organism to respond to stimuli in its environment, which is not related to biochemical processes.

3. **Identify the Correct Answer**: Since the question refers to the constant making and changing of biomolecules, it encompasses both the processes of building up and breaking down substances. Therefore, the correct term that describes this overall activity is **metabolism**.

4. **Conclusion**: The correct answer to the question is **metabolism**, as it includes all the biochemical activities in living organisms, including both anabolism and catabolism.

### Final Answer:
The activity of constantly making and changing chemicals/biomolecules in living organisms is known as **metabolism**.

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