Statement I : Plants form second trophic level. 

Statement II : Herbivores eat grass and form first trophic level.

Both statements I and II are incorrect .

The correct answer is Option (4) -Both statements I and II are incorrect .

The trophic levels in an ecosystem represent the different feeding positions of organisms in a food chain or food web. The primary trophic level consists of the producers, which are typically plants that produce their own food through photosynthesis or chemosynthesis. The secondary trophic level includes the primary consumers, which are herbivores that feed directly on plants.

Statement I: Plants form the second trophic level. This statement is incorrect. Plants are the primary producers in an ecosystem, and they form the first trophic level. They occupy the bottom of the food chain and serve as the primary source of energy for all other organisms. The energy flow starts from plants, and then it moves to herbivores (primary consumers) and then to carnivores (secondary consumers) and so on, forming subsequent trophic levels.

Corrected Statement I: Plants form the first trophic level.

Statement II: Herbivores eat grass and form the first trophic level. This statement is incorrect. Herbivores are animals that consume plant material as their primary source of food. They are the primary consumers and form the second trophic level in the food chain. Grass is a common food source for many herbivores, such as deer, cows, and grasshoppers. When herbivores consume grass, they obtain energy from the plant material, and this energy becomes available to the next trophic level when these herbivores are consumed by secondary consumers, such as carnivores or omnivores.

In summary:

• Plants (producers) form the first trophic level.
• Herbivores (primary consumers) eat grass and form the second trophic level by consuming plants.