Environment

Write the name and formula of a molecule made up of three atoms of oxygen. [All India]

Define ozone layer?

What are the after effects of ozone depletion?

Name the process by which the volume of solid wastes can be reduced.

Write the full form of CFC. Give its one harmful effect.

What are the causes of depletion of ozone layer ? Which diseases are likely to be caused if the ozone layer will become thinner ?

Write the harmful effects of ozone depletion.

Why are crop fields known as artificial ecosystems?

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

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

Why is it necessary to manage our garbage?

(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.

What percentage of the solar energy is trapped and utilised by the plants ?

Which radiations are absorbed by ozone layer ?

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

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

What is sewage ? How is sewage disposed of ?

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

How is the increase in demand for energy affecting our environment adversely?

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

Which disease is caused in human beings due to depletion of ozone layer in the atmosphere? [Foreign]

How is ozone formed in the upper atmosphere? Why is the damage of ozone layer a cause of concern to us? State a cause of this damage. [Delhi(C)]

Why is it necessary to conserve our environment? [All India]

What is the role of decomposers in the ecosystem? [Foreign]

List two man-made ecosystems. [All India]

Why is the ozone layer loss more in cold regions?

Fill in the following blanks with suitable words : Fill in the following blanks with suitable words :
(a) Decomposer organisms are……………. in their action.
(b) In nature, all green plants are……………. whereas animals are consumers.
(c) A series of organisms, each of which feeds on the next organism, the beginning of which is a green plant, is called a…………….
(d) The science that deals with the inter-relationships of living things with one another and their environment is called …………….
(e) Plastic is a……………. material whereas paper is a……………. material.

What is meant by a primary consumer, secondary consumer and a tertiary consumer ? Give one example of each.

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

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

Name two waste materials which can be recycled.

State whether the following statement is true or false :
Only 10 per cent of the light energy given by the sun is available for transfer at each higher trophic level in a food chain.

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

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

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

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

Why are some substances non- biodegradable? [Foreign]

Which class of chemicals is linked to the decrease in the amount of ozone in the upper atmosphere of the earth? [Delhi]

Explain the effects of human activity on the environment?

Which one of the following is not a terrestial ecosystem ?
Forest, Grassland, Aquarium, Desert

What are planktons ?

A food chain represents a unidirectional flow of X. What is X ?

Explain the terms ‘producer’ and ‘consumer’. Give two examples of producers and two of consumers.

The number of malaria patients in a village increased tremendously when large number of frogs were exported from the village. What could be the cause for it ?

What percentage of energy available at the producer level is transferred at successive trophic levels in a food chain ?

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

Where does all the energy in living organisms originate from ?

Explain how harmful chemicals enter our bodies.

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

State two advantages of using disposable paper cups over disposable plastic cups.