Question

Which of the following statements about pollen grains is incorrect?

• A. Vegetative cell is bigger and generative cell is smaller
• B. The outer layer of pollen grain, called exine, is made up of sporopollenin
• C. Pollen grains lose their viability immediately after being released from the anther
• D. Pollen grains are produced in the ovule of a flower

Hint:

Remember: Anther produces pollen grains (male gametophyte), whereas ovule produces the embryo sac (female gametophyte).

Answer 1

The Correct Option is D

Concept: Pollen grains are the male gametophytes of flowering plants. They are produced inside the microsporangia of the anther and play an essential role in plant reproduction. A mature pollen grain generally consists of a larger vegetative cell and a smaller generative cell enclosed within protective walls known as exine and intine. To identify the incorrect statement, each option must be analyzed carefully using the structure and development of pollen grains.

Step 1: Examine Option (A)
A mature pollen grain generally contains two unequal cells. The larger cell is called the vegetative cell, while the smaller cell is known as the generative cell. The vegetative cell contains abundant cytoplasm and food reserves, whereas the generative cell ultimately gives rise to two male gametes. Therefore, Option (A) is a correct statement.

Step 2: Examine Option (B)
The outer wall of the pollen grain is called the exine. Exine is composed of sporopollenin, one of the most resistant organic substances known in nature. It is highly resistant to high temperatures, strong acids, strong alkalis, and enzymatic degradation. Therefore, Option (B) is also correct.

Step 3: Examine Option (C)
Although pollen viability decreases after release from the anther, pollen grains do not always lose viability immediately. In cereals such as rice and wheat, viability may last for only a few minutes, whereas in many other flowering plants, pollen grains can remain viable for several days, weeks, or even months under suitable conditions. Thus, the statement is scientifically inaccurate.

Step 4: Examine Option (D)
Pollen grains are produced inside the anther, specifically within the microsporangia or pollen sacs. The ovule is a female reproductive structure that produces the embryo sac, not pollen grains. Hence, Option (D) is clearly incorrect. Conclusion: Pollen grains are produced in the anther and not in the ovule. \[ \boxed{\text{(D) Pollen grains are produced in the ovule of a flower}} \]