Our Environment — Class 10 Science PYQs

Which of the following group is not 'biodegradable' ?

Given below is a pyramid showing various trophic levels in an ecosystem :
(iv) Tertiary consumers
(iii) Secondary consumers
(ii) Primary consumers
(i) Producers
(a) From the organisms listed below, identify which one is to be placed at which trophic level ?
Deer, Grass, Lion, Snake, Rabbit
(b) Discuss the reason why primary consumers will have more energy as compared to secondary consumers ?
(c) Why is the base of the pyramid broad ?

Which of the following groups do not constitute a food chain ?
(i) Wolf, rabbit, grass, lion
(ii) Plankton, man, grasshopper, fish
(iii) Hawk, grass, snake, grasshopper, frog
(iv) Grass, snake, wolf, tiger

The percentage of solar energy which is not converted into food energy by the leaves of green plants in a terrestrial ecosystem is about :

Assertion (A) : The amount of ozone in the atmosphere began to drop sharply in the 1980s.
Reason (R) : The oxygen atoms combine with molecular oxygen to form ozone.

"Excessive use of chemicals and pesticides in agriculture adversely effect the environment." Justify this statement.

Identify from the following a group containing all non-biodegradable substances.

Write the essential function performed by ozone at the higher levels of the atmosphere. How is it formed in the upper atmosphere ? Write the name of the group of chemicals mainly responsible for the depletion of ozone layer.

Some harmful chemicals get accumulated in human bodies through the food chain. Name this phenomenon. Explain the reason of maximum concentration of these chemicals found in our bodies.

Identify the food chain in which the organisms of the second trophic level are missing :