Question

Which of the following ecological food chains does not represent an erect pyramid of numbers?
(a)Grass- Rodent- Snake
(b)Insect- Chicken- Human
(c)Tree- Bird- Parasite
(d)Grass- Deer- Tiger

Answer 1

The pyramid represents the quantity of energy at each trophic level of the food chain. It is often observed that these pyramids are within the shape of actual pyramids with the bottom being the broadest, which is roofed by the bottom trophic level.

Complete answer:
Pyramid of numbers is the pyramid that represents the entire number of people during a population at a special trophic level. Depending upon the amount, the pyramid of numbers might not be upright or inverted. In an erect pyramid of numbers, the amount of numbers is reduced from lower level to higher trophic level. It is seen in the grassland ecosystem. Ecological food chain of grass (which is producers) - grasshopper/deer (which are herbivores) - rodents/tiger (which are primary carnivores) - snakes (which are secondary carnivores) are the representatives of an erect pyramid of numbers. An insect (primary consumer) - chicken (secondary consumer) - human (tertiary consumer) is another sample of an erect pyramid of numbers. In an inverted pyramid of numbers, the amount of people increases from lower level to higher trophic level. It is seen in the tree ecosystem. Ecological food chain trees (which are producers) - birds (which are herbivores) - parasites are a sample of inverted pyramids of numbers.

Additional Information:
A pyramid of numbers shows graphically the population, or abundance, in terms of the amount of individual organisms involved at each level during an organic phenomenon. A pyramid of energy or pyramid of productivity shows the assembly or turnover (the rate at which energy or mass is transferred from one trophic level to the next) of biomass at each trophic level.
A pyramid of biomass shows the interconnection between biomass and trophic level by quantity of the biomass present at different trophic levels of an ecological community at a particular time. It's a graphical illustration of biomass (total amount of living or organic matter in an ecosystem) present within the unit area in various trophic levels.
So, the correct answer is 'Tree - Bird - parasite.'

Note: Producer – they are normally a green plant that creates its own food by photosynthesis
Primary Consumer – they are the animals that consume only plant matter. They're herbivores - e.g. rabbits, caterpillars, cows, sheep, and deer.
Secondary Consumer – they're the animals, which consume primary consumers (herbivores).