Read the following statements and determine the incorrect one .

Options

A. When pollen is shed at two - celled stage single fertilization takes place
B. Vegetative cell is larger than generative cell
C. Pollen grains in some plants remain viable for months
D. Intine is made up of cellulose and pectin

Answer

To determine the incorrect statement among the given options, we will analyze each statement one by one.

1. **Statement 1**: "When pollen grain is shed at two cell stage, single fertilization takes place."
- This statement is incorrect. In flowering plants (angiosperms), when pollen grains are shed, they typically contain two cells: a vegetative cell and a generative cell. However, the process of fertilization involves two male gametes, leading to double fertilization, not single fertilization. One male gamete fertilizes the egg cell, and the other fuses with the central cell to form the triploid endosperm.

2. **Statement 2**: "Vegetative cell is larger than generative cells."
- This statement is correct. The vegetative cell is indeed larger than the generative cell within the pollen grain.

3. **Statement 3**: "Pollen grain in some plants remain viable for months."
- This statement is also correct. Pollen grains can remain viable for extended periods, sometimes lasting for months, depending on the species and environmental conditions.

4. **Statement 4**: "Entine is made up of cellulose and pectins."
- This statement is correct. The inner layer of the pollen grain, known as entine, is composed of cellulose and pectins.

Based on the analysis, the incorrect statement is:

**Final Answer**: The incorrect statement is: "When pollen grain is shed at two cell stage, single fertilization takes place."