CBSE Class 10 Biology Sustainable Management of Natural Resources MCQs Set 23

Answer: (d) All of the above

Explanation:
1. Coliform count, BOD and pH are all used to assess water quality.
2. So all the options are correct.

Teacher's Note:
1. Coliform bacteria indicate sewage contamination.
2. BOD shows the organic load.

Answer: (a) Coliform bacteria

Explanation:
1. Coliform bacteria (like E. coli) from human intestines are used to measure sewage pollution.
2. Their count in Ganga water was very high.

Teacher's Note:
1. They are found in faeces.
2. They cause stomach infections.

Answer: (a) Afforestation

Explanation:
1. Tree roots hold the soil together and leaves reduce the force of rain.
2. So afforestation prevents erosion.

Teacher's Note:
1. Deforestation and overgrazing increase erosion.
2. Contour farming also helps.

Answer: (d) It causes soil erosion

Explanation:
1. Forests supply raw materials, resin, gum and drugs, and help control floods.
2. They prevent, not cause, soil erosion.

Teacher's Note:
1. Forests also keep the climate balanced.
2. They are home to wildlife.

Answer: (b) Habitat destruction

Explanation:
1. The main cause is the destruction of habitats, which removes food and shelter.
2. Afforestation helps wildlife.

Teacher's Note:
1. Hunting is another cause.
2. Protected areas safeguard habitats.

Answer: (a) Afforestation

Explanation:
1. Van Mahotsava is an annual tree-planting festival held in July.
2. It promotes afforestation.

Teacher's Note:
1. It was started in 1950 by K. M. Munshi.
2. Planting trees helps the environment.

Answer: (b) A gift of nature which is very useful to mankind

Explanation:
1. Natural resources are materials provided by nature that people can use.
2. Examples are air, water, soil and minerals.

Teacher's Note:
1. They are not man-made.
2. They are found on land, in water and in air.

Answer: (c) Forests do not conserve soil

Explanation:
1. Forests do conserve soil because roots bind it.
2. The other statements are true.

Teacher's Note:
1. They also help in recharging groundwater.
2. Roots slow down run-off.

Answer: (d) All of the above

Explanation:
1. Forests produce wood and other products, protect soil and water, and regulate climate.
2. So all the options are correct.

Teacher's Note:
1. These are the three main functions.
2. Forests are called the lungs of the earth.

Answer: (b) Rajasthan

Explanation:
1. The Indira Gandhi Canal brings river water to the desert of Rajasthan.
2. It has turned dry lands green.

Teacher's Note:
1. The canal starts from the Harike barrage.
2. It is one of the longest canals in India.

Answer: (d) All of the above

Explanation:
1. Large dams displace people, cost much money and damage the environment.
2. So all three reasons apply.

Teacher's Note:
1. The Narmada and Tehri dams were protested against.
2. Benefits of dams include power and irrigation.

Answer: (d) Both surface water and groundwater but not ocean water

Explanation:
1. We manage and conserve surface water (rivers, lakes) and groundwater.
2. Ocean water is not used for ordinary needs.

Teacher's Note:
1. Salt water needs desalination.
2. Water harvesting stores rain water.

Answer: (b) Uttarakhand

Explanation:
1. The Chipko movement started in the Garhwal Himalayas in present-day Uttarakhand.
2. Villagers hugged trees to stop them being cut.

Teacher's Note:
1. Sundarlal Bahuguna was its leader.
2. The movement started in the 1970s.

Answer: (a) A. K. Banerjee

Explanation:
1. A. K. Banerjee of West Bengal started joint forest management at Arabari.
2. Villagers helped protect the sal forest in return for some benefits.

Teacher's Note:
1. The degraded sal forest was revived.
2. People's participation is important in conservation.

Answer: (c) Amrita Devi

Explanation:
1. Amrita Devi Bishnoi led the villagers to protect khejri trees in 1731.
2. She and many others were killed.

Teacher's Note:
1. She is remembered as a martyr of conservation.
2. The Amrita Devi Bishnoi Wildlife Protection Award is named after her.

Answer: (c) Himachal Pradesh

Explanation:
1. Kuhls are channels carrying water from glaciers or streams to fields in Himachal Pradesh.
2. They are an old water harvesting system.

Teacher's Note:
1. They irrigate terraced fields.
2. Each region has its own water system.

Answer: (d) All of the above

Explanation:
1. Khadins, tanks and nadis are all old methods of storing rain water in Rajasthan.
2. So the answer is all of these.

Teacher's Note:
1. A nadi is a village pond.
2. These methods suit dry regions.

Answer: (c) Water harvesting

Explanation:
1. These are traditional structures for catching and holding rain water.
2. They recharge groundwater.

Teacher's Note:
1. Each is used in a different region.
2. They are low-cost and sustainable.

Answer: (b) Stimulates the growth of grasses

Explanation:
1. Moderate grazing removes old leaves and encourages new growth.
2. Overgrazing, however, destroys grassland.

Teacher's Note:
1. Grass grows from the base, so it recovers after cutting.
2. Balance is the key.

Answer: (d) Forests

Explanation:
1. Hotspots are regions rich in species that are under threat, and are mostly forested areas.
2. India has hotspots in the Western Ghats and the Himalayas.

Teacher's Note:
1. They have many endemic species.
2. They are priority areas for conservation.

Answer: (a) Earthen embankment down the slope

Explanation:
1. A khadin is a long earthen embankment built across the lower edge of a sloping field to trap run-off water.
2. The water soaks in and crops are grown in the moist land.

Teacher's Note:
1. It is used in Jaisalmer in Rajasthan.
2. The idea is to store water in the soil.

Answer: (c) (i) and (iii)

Explanation:
1. Biodiversity means variety of plants and animals, and forests have the highest variety.
2. It does not mean flora only or the number of individuals of one species.

Teacher's Note:
1. Forests provide many habitats.
2. Loss of habitat reduces biodiversity.

Answer: (d) Using windmills to generate power for irrigation

Explanation:
1. Windmills use wind energy, which is clean and renewable.
2. The other activities cause pollution.

Teacher's Note:
1. Cars burn fuel and polybags do not decay.
2. Dyes pollute water.

Answer: (d) All of these

Explanation:
1. Burning fossil fuels gives CO₂, CO, and oxides of nitrogen and sulphur.
2. So all are released.

Teacher's Note:
1. They cause pollution and global warming.
2. Incomplete combustion gives CO.

Answer: (d) Both exhaustible and non-renewable resource

Explanation:
1. Petroleum formed over millions of years and cannot be renewed in a short time.
2. It is both an exhaustible and a non-renewable resource.

Teacher's Note:
1. Coal and natural gas are also non-renewable.
2. We must use them carefully.

Answer: (c) Electricity

Explanation:
1. Electricity is produced by people using other resources.
2. Soil, water and air occur naturally.

Teacher's Note:
1. Natural resources occur in nature.
2. Electricity is man-made energy.

Answer: (b) 40 years and 200 years respectively

Explanation:
1. Estimates say petroleum will last about 40 years and coal about 200 years.
2. So petroleum is going to be used up much sooner.

Teacher's Note:
1. These estimates change with new discoveries.
2. This is why we must save fuel.