Question

A field scientist counted the number of individuals of the following from a place but jumbled up the titles of the datasheet. The organisms have been enlisted below:
i. Grass
ii. Hawks
iii. Sparrows
iv. Plant bugs
Which one of the following combinations represent the most appropriate numbers of each of the above organisms in the sequence mentioned above?

• A. 13254, 5, 8376, 279
• B. 8379, 279, 5, 13254
• C. 13254, 279, 8376, 5
• D. 13254, 5, 279, 8379

Answer 1

The correct option is D 13254, 5, 279, 8379

Based on the source of their nutrition or food, organisms occupy a specific place in the food chain that is known as their trophic level. Producers belong to the first trophic level, herbivores (primary consumer) to the second and carnivores (secondary consumer) to the third. Hence, the food chain is as follows: grass $\to$ plant bugs $\to$ sparrow $\to$ hawk.

Now, in a grassland ecosystem, the number of producers (mainly grasses) is always maximum, followed by decreasing numbers in subsequent trophic levels with a minimum at the apex. Thus, a pyramid of numbers in grassland ecosystem is upright. Hence, the number of organisms at each trophic levels are as follows:
Grass (13254), plant bugs (8379), sparrows (279), hawk (5). So, the correct option is d.