Question

Transgenic Brassica napus has following feature

• A. Rich in vitamin-C
• B. Herbicide tolerant
• C. Insect resistance
• D. Male sterility

Hint:

The Barnase gene induces male sterility, while the Barstar gene restores male fertility.
This dual-gene system is a powerful tool for hybrid seed production in self-pollinating crops.

Answer 1

The Correct Option is D

Step 1: Recall the goal behind engineering Brassica napus.
Hybrid seed production in this crop relies on preventing self-pollination, which means the plant used as the female parent must not produce viable pollen.
Step 2: Recall the tool used to achieve this.
The barnase gene, taken from a bacterium, is expressed specifically in the tapetum layer of the anther, where it destroys the tissue that would otherwise nurture developing pollen.
Step 3: Read off the resulting trait.
A plant carrying this gene simply cannot produce functional pollen.
Final answer: Option 4, Male sterility.