Question

What would happen if green plants disappear from earth?
A. Only herbivores die
B. Only carnivores die
C. No one dies
D. Both herbivores and carnivores die

Answer 1

Hint: Green plants occupy the first trophic level since they are producers which makes food and energy for other organisms too. Herbivores feed on producers and carnivores feed on herbivores.

Complete answer:
First of all, you should know what herbivores and carnivores are. Herbivores are animals which are adapted automatically to eating plant material or you can say they feed on green plants which is their main component as diet and these have mouthparts adapted to grinding. These are known as primary consumers as they feed on autotrophs such as plants, algae.
Carnivores are the animals which feed on the herbivores in order to live as their main food component. They derive food and energy from animal tissue or the meat by hunting or scavenging. These are completely dependent on animal flesh for their nutrient requirements.

So, if we look at options;
> Option A: Only herbivores die then this option is not the correct one since if the green plants will disappear then not only herbivores will die but then carnivores will not be able have their food and energy requirement since they feed on herbivores and hence they will also die. Therefore this option is not the correct one and it gets eliminated.

> Option B: Only carnivores die. This option is incorrect since if green plants will disappear then herbivores will die first as herbivores feed on plants for food and then carnivores will die which means not only carnivores but herbivores and carnivores both will die. Therefore, this option is incorrect and it gets eliminated.

> Option C: No one dies. This cannot be the correct one since green plants are an important source of food for all organisms and if they disappear then all organisms will die ultimately. Therefore, this option is incorrect one.

> Option is D: Both herbivores and carnivores. Green plants are a source of food for all the organism and if green plants will disappear then herbivores and carnivores both will die because herbivores feed on green plants for food and further carnivores depend on herbivores for food and energy. Therefore, this option is the correct one.

Hence, the correct answer is option (D).

Note: Herbivores feed on green plants for food and energy and if green plants will disappear then there will be no food and energy for herbivores and ultimately herbivores will die. But in the food chain, carnivores feed on herbivores and if herbivores will die then carnivores will also die out of food and energy.