Which one of the following is not a polymeric substance?

Options

A. Rubber
B. Morphine
C. Gum
D. Cellulose

Answer

To determine which of the following options is not a polymeric substance, we need to analyze each option provided in the question.

### Step-by-Step Solution:

1. **Identify the options**: The question provides several options, which we need to evaluate to see if they are polymers or not.

2. **Evaluate Rubber**:
- Rubber is a polymer made from isoprene units.
- Since it is formed by the polymerization of isoprene, it is indeed a polymer.

3. **Evaluate Gum**:
- Gum is also a polymer, specifically a polysaccharide, which is made up of repeating units of sugars (often derived from isoprene).
- Therefore, gum is a polymeric substance.

4. **Evaluate Cellulose**:
- Cellulose is a polysaccharide made up of glucose units.
- It is a polymer because it consists of long chains of repeating glucose molecules.

5. **Evaluate Morphine**:
- Morphine is classified as an alkaloid and is not a polymer.
- It is a small organic molecule and does not consist of repeating units like a polymer does.

6. **Conclusion**:
- Based on the evaluations, the only substance that is not a polymeric substance is morphine.
- Therefore, the correct answer is option B: Morphine.

### Final Answer:
Morphine is not a polymeric substance.

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