Biology

Environment

Question:

Why are plants called producers ?

Answer:

Plants are called producers because green plants prepare their own food from simple inorganic substances like carbon dioxide and water by using sunlight energy in the presence of chlorophyll.

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Environment

Q 1.

What will happen if we kill all the organisms in one trophic level? [Delhi]

Q 2.

What is pollution?

Q 3.

Name two predators of snakes in a food web operating in a forest ecosystem.

Q 4.

(a) Define decomposers. Name one decomposer.
(b) What is the role of decomposers in the ecosystem ?

Q 5.

Which category of organisms forms the starting point of a food chain ?

Q 6.

Explain how, harmful ultraviolet radiations of sunlight are prevented from reaching the earth’s surface.

Q 7.

(a) What is meant by non-biodegradable waste materials ? Give two examples of non-biodegradable wastes.
(b) Which of the following materials are biodegradable ?Animal bones, Iron nails, Plastic mugs, Leather belts, Silver foil

Q 8.

Suggest any four activities in daily life which are eco-friendly.

Q 9.

Give an example to illustrate that indiscriminate use of pesticides may result-in the degradation of the environment. [All India]

Q 10.

Explain the effects of human activity on the environment?

Q 11.

Which of the following are biodegradable and which non-biodegradable ?
Glass bottle, Paper, Ball point pen refill, Hay, DDT, Wheat, Cake, Wood,
Polythene bag, Jute bag, Cotton cloth, Grass, Vegetable peels

Q 12.

Where does all the energy in living organisms originate from ?

Q 13.

Fill in the following blanks with suitable words :Fill in the following blanks with suitable words :
(a) Ultraviolet rays can cause skin…………………
(b) Pesticides enter the food chain at the…………………. level
(c) Grass →…………….→Human
(d) Lettuce →…………….→ Fox
(e) Plants→ Antelope→  …………….

Q 14.

Write the harmful effects of ozone depletion.

Q 15.

What are the advantages of cloth bags over plastic bags during shopping?

Q 16.

Explain some harmful effects of agricultural practices on the environ-ment.

Q 17.

Name any two abiotic components of an environment. [Delhi (C)]

Q 18.

What are the two main components of our environment? [Delhi]

Q 19.

Why did United Nations act to control the production of chlorofluorocarbons (CFCs) used in refrigerators? [Delhi]

Q 20.

What happens when higher energy ultraviolet radiations act on the oxygen at the higher level of the atmosphere? [All India]

Q 21.

In a food chain, 10,000 joules of energy is available to the producer. How much energy will be available to the secondary consumer to transfer it to the tertiary consumer? [All India ]

Q 22.

Name two natural ecosystems and two artificial ecosystems.

Q 23.

What name has been given to those organisms which break down the complex organic compounds present in dead animals and plants ?

Q 24.

What are the various steps of food chain called ?

Q 25.

Which organisms belong to third and fourth trophic levels in the food chain comprising the following ?
Rats, Plants, Hawk, Snakes

Q 26.

Can the organisms of any trophic level be removed without causing any damage to the ecosystem ? Will the impact of removing all the organisms in a trophic level be different for different trophic levels ?

Q 27.

Consider the food chain :
Grass → Deer → Lion
What will happen if all the lions are removed from the above food chain ?

Q 28.

How does a biodegradable waste differ from a non-biodegradable waste ? Give two examples of non- biodegradable wastes which pollute our environment.

Q 29.

We do not clean ponds or lakes but an aquarium needs to be cleaned periodically. Why ?

Q 30.

What will be the consequence of the absence of decomposers in the ecosystem ?

Q 31.

(a) What is meant by ‘environment’ ?
(b) What type of substances are the major pollutants of the environment ? Name two such substances.
(c) Name the organisms whose uncontrolled activities are damaging the environment.
(d) Explain why, it is better to use paper bags than plastic bags.

Q 32.

Name the process in which a harmful chemical enters the food chain and gets concentrated at each trophic level.

Q 33.

In a food chain consisting of grass, frog, bird and insects, where will the concentration of the harmful chemicals be maximum ?

Q 34.

If a harmful chemical enters a food chain comprising cat, mice and plants, which one of these organisms is likely to have the maximum concentration of the harmful chemical in its body ?

Q 35.

Name the group of chemical compounds which damages the ozone layer.

Q 36.

‘If we excessively use pesticides to protect the crops from diseases, then it may cause long-term damage to mankind’. Justify this statement.

Q 37.

Name the various modes of waste disposal.

Q 38.

How can the wastes such as paper, plastic and metal objects be disposed of ?

Q 39.

Give a method for the disposal of household wastes such as left-over food, fruit and vegetable peels, and leaves of potted plants.

Q 40.

What is meant by incineration ? For what purpose is it used ?

Q 41.

How are most of the solid wastes in urban areas disposed of ?

Q 42.

What is sewage ? How is sewage disposed of ?

Q 43.

What would happen if the ozone layer in the atmosphere completely disappears ?

Q 44.

(a) With the help of a flow diagram, describe how energy from the sun flows through various trophic levels.
(b) Explain why, the flow of energy in the ecosystem is said to be unidirectional.

Q 45.

Write the common food chain of a pond ecosystem.

Q 46.

Why are crop fields known as artificial ecosystems?

Q 47.

We do not clean ponds or lakes, but an aquarium needs to be cleaned. Why?

Q 48.

Name the wastes which are generated in your house daily. What measures would you take for their disposal?

Q 49.

Why is ozone layer getting depleted at the higher levels of the atmosphere? [Delhi (C)]

Q 50.

Why are bacteria and fungi called decomposers? List any two advantages of decomposers to the environment. [Delhi]