Which of the following is a heteropolymer ?

Options

A. Cellulose
B. Peptidoglycan
C. Starch
D. Glycogen

Explanation

To determine which of the following is a heteropolymer, we need to understand the definition of a heteropolymer and analyze the given options.

### Step-by-Step Solution:

1. **Understand the Definition of Heteropolymer:**
- A heteropolymer is a type of polymer that is made up of different types of monomeric units. This means that it consists of more than one kind of repeating unit.

2. **Analyze the Options:**
- We need to evaluate each option to see if it fits the definition of a heteropolymer.

3. **Option 1: Cellulose**
- Cellulose is a polymer made up of repeating units of glucose. Since it consists of only one type of monomer, it is classified as a homopolymer.
- **Conclusion:** Cellulose is NOT a heteropolymer.

4. **Option 2: Peptidoglycan**
- Peptidoglycan is composed of two different monomeric units: N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM).
- Since it contains different types of monomers, it qualifies as a heteropolymer.
- **Conclusion:** Peptidoglycan IS a heteropolymer.

5. **Option 3: Starch**
- Starch is another polymer made up entirely of glucose units. It consists of only one type of monomer.
- **Conclusion:** Starch is NOT a heteropolymer.

6. **Option 4: Glycogen**
- Glycogen, like starch, is also a polymer made up solely of glucose units. It is a homopolymer.
- **Conclusion:** Glycogen is NOT a heteropolymer.

7. **Final Answer:**
- After analyzing all the options, the only heteropolymer among the given choices is **peptidoglycan**.

### Summary:
The correct answer to the question "Which of the following is a heteropolymer?" is **peptidoglycan**.