Question

Statement 1: In a food chain, number of organisms at each successive level decreases.
Statement 2: Number of organisms at any trophic level depends upon the availability of food and energy.

• A. Both the statements are false
• B. Statement 1 is true but statement 2 is false
• C. Both the statements are true and statement 2 is the correct explanation for statement 1
• D. Statement 1 is not true but statement 2 is true

Answer 1

The correct option is D Statement 1 is not true but statement 2 is true

The number of organisms at any trophic level depends upon the amount of food and energy at the previous level. Therefore, most food chains will have a higher number of organisms at the producer level and the number decreases at each successive level.
But there are exceptions to this. For example, in a tree ecosystem, although the number of organisms at the first trophic level- the tree is just one, the number of organisms at the successive levels increases (the animals living on the tree). Therefore statement 1 is not always true.