Pectin occurs in

Options

A. Blood protein
B. Plant cell walls
C. Milk protein
D. Liver cells

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks where pectin occurs. It provides four options: blood protein, plant cell walls, milk protein, and liver cells.

2. **Analyzing the Options:**
- **Blood Protein:** Blood proteins include various types such as globulins and albumin, but they do not contain pectin.
- **Plant Cell Walls:** Pectin is a polysaccharide found in the cell walls of plants, playing a crucial role in their structure and growth.
- **Milk Protein:** Milk proteins primarily consist of casein and whey proteins, which do not include pectin.
- **Liver Cells:** Liver cells contain proteins like albumin but do not contain pectin.

3. **Identifying the Correct Option:**
Based on the analysis, the only option that correctly identifies where pectin occurs is "plant cell walls."

4. **Explaining the Role of Pectin:**
Pectin is an essential polysaccharide in the plant cell wall that contributes to the extension of the primary cell wall, which is vital for plant growth. It can be found in forms such as calcium pectate or magnesium pectate.

5. **Conclusion:**
Therefore, the correct answer to the question "Pectin occurs in" is **plant cell walls**.

---