Natural Resources MCQ 1
16. Which of the following is a recently originated problem of environment?
(a) Ozone layer depletion
(b) Green house effect
(c) Global warming
(d) All of the above
Ans. (d) All of the above
Explanation: All the problems mentioned here have originated after the industrial revolution.
17. When we breathe in air, nitrogen also goes inside along with oxygen. What is the
fate of this nitrogen?
(a) It moves along with oxygen into the cells
(b) It comes out with the CO2 during exhalation
(c) It is absorbed only by the nasal cells
(d) Nitrogen concentration is already more in the cells so it is not at all absorbed.
Ans. (b) It comes out with the CO2 during exhalation
Explanation: Nitrogen is the most abundant gas in the air and hence it goes inside our body during inhalation. But nitrogen is not utilized by the body and comes out during exhalation.
18. Top-soil contains the following
(a) Humus and living organisms only
(b) Humus and soil particles only
(c) Humus, living organisms and plants
(d) Humus, living organisms and soil particles.
Ans. (d) Humus, living organisms and soil particles.
19. Choose the correct sequences
(a) CO2 in atmosphere →decomposers → organic carbon in animals → organic carbon in plants
(b) CO2 in atmosphere →organic carbon in plants → organic carbon in animals → inorganic carbon in soil
(c) Inorganic carbonates in water →organic carbon in plants → organic carbon in animals → scavengers
(d) Organic carbon in animals →decomposers → CO2 in atmosphere → organic carbon in plants
Ans. (b) CO2 in atmosphere →organic carbon in plants → organic carbon in animals → inorganic carbon in soil
Explanation: Carbon dioxide from the atmosphere is utilized by green plants during photosynthesis. Thus, organic compounds are made in plants. When an animal takes food, organic compounds from plants go to the body or animal (directly or indirectly). Once an animal or a plant dies; decomposition of the dead remains result in formation of inorganic carbon in soil.
20. Major source of mineral in soil is the
(a) parent rock from which soil is formed
(b) plants
(c) animals
(d) bacteria
Ans. (a) parent rock from which soil is formed
21. Total earth’s surface covered by water is
(a) 75%
(b) 60%
(c) 85%
(d) 50%
Ans. (a) 75%
22. Biotic component of biosphere is not constituted by
(a) producers
(b) consumers
(c) decomposer
(d) air
Ans. (d) air
Explanation: Biotic components comprise of living beings. Air is a non-living thing and hence cannot be a part of biotic components.
23. An increase in carbon dioxide content in the atmosphere would not cause
(a) more heat to be retained by the environment
(b) increase in photosynthesis in plants
(c) global warming
(d) abundance of desert plants
Ans. (d) abundance of desert plants
Explanation: Desert does not have suitable condition for abundant growth of plants. A part from carbon dioxide; a plant also needs oxygen, water and minerals form proper growth and development. But water is a scarce resource in deserts.
24. Oxygen is returned to the atmosphere mainly by
(a) burning of fossil fuel
(b) respiration
(c) photosynthesis
(d) fungi
Ans. (c) photosynthesis
Explanation: Agents in other options return carbon dioxide to the atmosphere.
25. Low visibility during cold weather is due to
(a) formation of fossil fuel
(b) unburnt carbon particles or hydrocarbons suspended in air
(c) lack of adequate power supply
(d) none of these
Ans. (b) unburnt carbon particles or hydrocarbons suspended in air
Explanation: Unburnt carbon particles and hydrocarbons suspended in air create smog. Smog result in low visibility.
26. Growth of Lichens on barren rocks is followed by the growth of
(a) moss
(b) ferns
(c) gymnosperms
(d) algae
Ans. (a) moss
Explanation: Lichens secrete certain enzymes which break the rocks and make it suitable for growth of masses. Mosses further pave the way for formation of soil and for growth of higher plants.
27. Marked temperature changes in aquatic environment can affect
(a) breeding of animals
(b) more growth of aquatic plants
(c) process of digestion in animals
(d) availability of nutrients.
Ans. (a) breeding of animals
Explanation: Temperature change my hamper the growth of aquatic plants. Availability of nutrients in water does not depend on temperature but an availability of mineral in the substratum. Temperature change in water way affect digestion in aquatic animals but it will have no effect on digestion in land animals. Thus, other options can be ruled out.
28. Soil erosion can be prevented by
(a) raising forests
(b) deforestation
(c) excessive use of fertilizer
(d) overgrazing by animals
Ans. (a) raising forests
Explanation: Agents in other options will increase soil erosion.
29. What happens when rain falls on soil without vegetational cover?
(a) Rain water percolates in soil efficiently
(b) Rain water causes loss of surface soil
(c) Rain water leads to fertility of the soil
(d) Rain water does not cause any change in soil
Ans. (b) Rain water causes loss of surface soil
Explanation: plants hold top soul with their roots and thus prevent top soil from getting washed away by rain.
30. Oxygen is harmful for
(a) ferns
(b) nitrogen fixing bacteria
(c) chara
(d) mango tree
Ans. (b) nitrogen fixing bacteria
