Class 7 Science Chapter 12 MCQ

Forests serve as green lungs as they produce oxygen for breathing and respiration and help in maintaining oxygen and carbon dioxide balance in the atmosphere.

Here, all these statements are correct. Hence, your answer will be option [D].

As Boojho was entering the forest his class teacher told him not to make noise in the forest because it could disturb both birds and animals.

A tree has the strongest stem.

Here, all these statements are correct. Hence, your answer will be option [D].

The forest is an ecosystem consisting of living things such as plants, animals and decomposers and non-living things such as soil, water and air. In the forest ecosystem, there is an interaction between living things and non-living environment. When plants and animals die, then the decomposers organisms decompose their dead bodies into nutrients, water and carbon dioxide. Nutrients and water are returned to the soil, and carbon dioxide is returned to the air. These nutrients, water and carbon dioxide are then re-used for the growth of new plants in the forest. And this process goes on and on like an un-ending chain. Thus, we can say that the various components of a forest are interdependent on one another.

Porcupine is not the name of a tree rather it is an animal. Teak, Sal and Kachnar are names of trees.

From the above given options, semal and hornbill are the names of a tree and an animal, respectively.

he first step in every food chain is the plants. They are also referred as “Autotrophs”. The second step in a food chain is always a herbivore. The third step in a food chain is always a carnivore.

Here, all these statements are correct. Hence, your answer will be option [D].

The branchy part of a tree above the stem is known as the “Crown” of the tree. The crown includes the top part of a tree which has all the branches and leaves of the tree.

When plants and animals die, then the decomposers organisms decompose their dead bodies into nutrients, water and carbon dioxide, not oxygen. Where nutrients and water are returned to the soil, and carbon dioxide is returned to the air. These nutrients, water and carbon dioxide are then re-used for the growth of new plants in the forest. And this process goes on and on like an un-ending chain.

Here, all these statements are correct. Hence, your answer will be option [D].

Those animals which eat dead animals’ area called scavengers. Scavengers eat up the dead bodies of animals and a help in keeping forest environment clean. Vultures, crows, jackals, hyena, some insects and beetles are the example of scavengers. Without scavengers’ dead body of the forest animals could not be got rid of quickly. But they are not decomposers.

Scavengers are not referred as decomposers. Scavengers are a kind of cleansing agent of the environment. Without scavengers’ dead body of the forest animals could not be got rid of quickly. But they are not decomposers. Because, they do not break down dead animals into simpler substances which can be reused by the plants.

Here, all these statements are correct. Hence, your answer will be option [D].

The forest has a wide variety of animals. The type of animals also differ from forest to forest. The common animals which are found in forest in our country are monkey, jackal, elephants, tigers, lions, squirrel, porcupine, peacock, snakes, honey bees and other various small animals. The insects such as butterflies, honey bees and birds help in flowering plants of the forest in pollination not an Antelopes. An African animal with horns and long, thin legs that can run very fast. It looks like deer.

Here, all these statements are correct. Hence, your answer will be option [D].

Amount of CO2 in air will increase. Forests help in maintain water cycle in nature and hence bring sufficient rain. Forests prevent soil erosion and floods and hence help in the conservation of soil. Forests also maintain the balance between carbon di oxide and oxygen in the atmosphere. Destruction of forests can change the earth’s climate.

In a forest, trees form the uppermost layer followed by shrubs and the herbs form the lowest layer of vegetation

No body has planted any trees in the natural forests. The natural forests contain trees and plants which have grown on their own.

Destruction of forests would not prevent flooding of rivers, loss of life and property. Destruction of forests can change the earth’s climate. There would be no life without forest.

Here, all these statements are correct. Hence, your answer will be option [D].

Here, all these statements are correct. Hence, your answer will be option [D].

Green plants and trees of the forest supply oxygen for breathing and respiration, so forests are known as green lungs.