How Nature Works in Harmony MCQs for UPSC Prelims

If all the decomposers in a forest suddenly vanished, the most likely long-term result would be that

1. A dead leaves and remains would pile up and the soil would grow poorer in nutrients
2. B nothing would change, since decomposers feed only on waste
3. C plants would grow faster because nothing would compete with them
4. D every herbivore in the forest would die within a day

Pollination is important for our food supply because

1. A pollination kills the pests that attack a crop
2. B pollination adds nutrients to the soil of a field
3. C many crops form fruits and seeds only after their flowers are pollinated
4. D pollination supplies water to the growing crop

Assertion (A): A pond is an example of an ecosystem. Reason (R): Water plants in a pond make their own food using sunlight.

1. A Both A and R are true, and R is the correct explanation of A
2. B Both A and R are true, but R is not the correct explanation of A
3. C A is true, but R is false
4. D A is false, but R is true

Plastic bags thrown into open drains in a town commonly lead to

1. A more dissolved oxygen in the drain water
2. B a faster flow of water through the drains
3. C cleaner drains that need less maintenance
4. D blocked drains and water logging during heavy rain

Green plants are called producers because

1. A they release oxygen only at night
2. B they are rooted in one place
3. C they make their own food using sunlight
4. D they take in ready-made food from the soil

Non-biodegradable waste is waste that

1. A breaks down completely within a few days
2. B is always in liquid form
3. C is always dangerous to touch
4. D cannot be broken down by decomposers