The proteins encoded by Cry1ac and Cry2ab genes act on which of the following:

The correct option is C

Boll worm

The correct option is C

Explanation of the correct option:

1. Boll worms are a variety of pests that act on the cotton plant and cause a major decrease in their yield.
2. The Cry1ac and Cry2ab genes are encoded by an organism known as Bacillus thuringiensis.
3. These genes code for a toxin protein that causes lysis in the gut of the bollworms.
4. The protein acts as a toxin when ingested by the pests.
5. The protein becomes activated after reaching the gut of pests.
6. The alkaline pH in the gut of the intestine activates the protein and creates pores in the intestine and kills the pests.
7. In the cotton plant, the formation of genetically modified pants was called the Bt Cotton plant.
8. These genes help in killing the pests that affect the yield of the cotton plant.

Explanation of the incorrect options:

Option A:

1. Nematodes are worms that do not possess any segmentation.
2. Very few species are known to cause plant diseases.
3. Most nematodes are known to have a beneficial effect on the quality of the soil.

Option B:

1. A pinworm is a parasitic nematode.
2. It is mostly found in the intestines of organisms.

Option D:

A bookworm can be considered as an insect that gnaws through the binding of the books and their pages, hence causing damage to it.

Final answer: The proteins encoded by Cry1ac and Cry2ab genes act on bollworms.