Biology

Environment

Question:

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

Answer:

If all the lions are removed, then there will be no predator control over the population of deer due to which its populations will greatly increase and deer will eat all grass. Over grazing will eliminate the grass and other green plants completely and turn the lush green forest into a desert area having no vegetation at all.

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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.

(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 7.

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

Q 8.

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

Q 9.

Explain the effects of human activity on the environment?

Q 10.

Where does all the energy in living organisms originate from ?

Q 11.

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 12.

Write the harmful effects of ozone depletion.

Q 13.

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

Q 14.

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

Q 15.

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

Q 16.

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

Q 17.

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

Q 18.

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

Q 19.

Name two natural ecosystems and two artificial ecosystems.

Q 20.

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

Q 21.

What are the various steps of food chain called ?

Q 22.

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

Q 23.

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 24.

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 25.

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

Q 26.

(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 27.

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

Q 28.

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

Q 29.

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

Q 30.

Name the various modes of waste disposal.

Q 31.

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

Q 32.

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

Q 33.

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

Q 34.

What is sewage ? How is sewage disposed of ?

Q 35.

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

Q 36.

(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 37.

Write the common food chain of a pond ecosystem.

Q 38.

Why are crop fields known as artificial ecosystems?

Q 39.

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

Q 40.

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

Q 41.

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

Q 42.

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

Q 43.

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

Q 44.

Why are green plants called ‘producers’? [All India]

Q 45.

State two problems caused by the non- biodegradable waste that we generate in our daily life. [All India (C)]

Q 46.

Construct an aquatic food chain showing four trophic levels. [All India]

Q 47.

Explain the phenomenon of “biological magnification” How does it affect organisms belonging to different trophic levels particularly the tertiary consumers? [Delhi]

Q 48.

Define ‘trophic level’. [Delhi]

Q 49.

What are the various steps in a food chain called? [Delhi]

Q 50.

What is the important function of presence of ozone in earth’s atmosphere? [Delhi]