What would happen if the food chain below was without deer? Grass→Deer→Tiger→

i. The population of tigers increases

ii. The population of grass decreases

iii. Tigers will start eating grass

iv. The population of tigers decreases and the population of grass increases.

                                           (OR)

A number of lower trophic levels organisms are fed by higher trophic levels constitute the____

i. Food web

ii. Ecological pyramid

iii. Ecosystem

iv. Food chain

If deer are missing from the given food chain, then the population of tigers will decrease as they will not have deer for their food and will starve to death. The grass population will also increase as there is no organism to consume grass as food.

Hence option (d) The population of tigers decreases and the population of grass increases, is correct.

                                               (OR)

Organisms of a higher trophic level feeding on several types of organisms belonging to a lower trophic level constitute a food web. It is a complex network of many interdependent food chains. The food chain is a single chain of organisms feeding on one another. The food pyramid is a diagrammatic representation of the type and proportion of food items eaten by human beings for a healthy life. An ecosystem is a combination of living and non-living components.

Hence option (a) food web is correct.