Question:
Write the full form of CFC. Give its one harmful effect.
Answer:
CFC – Chlorofluorocarbons. Chlorofluorocarbons released into the air react with ozone gas present in the ozone layer and destroy it gradually.
Environment
Q 1.
Why are some substances non- biodegradable? [Foreign]
Q 2.
What is garbage ? What does garbage consist of ?
Q 3.
Name the phenomenon in which non-biodegradable chemicals get accumulated progressively at each trophic level of a food chain.
Q 4.
What is the functional unit of the environment comprising of the living and non-living components called ?
Q 5.
Which one of the following is not a terrestial ecosystem ?
Forest, Grassland, Aquarium, Desert
Q 6.
Name two waste materials which can be recycled.
Q 7.
Where does all the energy in living organisms originate from ?
Q 8.
What is sewage ? How is sewage disposed of ?
Q 9.
Write the harmful effects of ozone depletion.
Q 10.
What would happen if the ozone layer in the atmosphere completely disappears ?
Q 11.
What is a food web?
Q 12.
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 13.
Write the common food chain of a pond ecosystem.
Q 14.
Why is ozone layer getting depleted at the higher levels of the atmosphere? [Delhi (C)]
Q 15.
What is the important function of presence of ozone in earth’s atmosphere? [Delhi]
Q 16.
List out the components in a food chain?
Q 18.
What are planktons ?
Q 19.
(a) Define decomposers. Name one decomposer.
(b) What is the role of decomposers in the ecosystem ?
Q 20.
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 ?
Q 21.
Explain how harmful chemicals enter our bodies.
Q 22.
Give a method for the disposal of household wastes such as left-over food, fruit and vegetable peels, and leaves of potted plants.
Q 23.
State two advantages of using disposable paper cups over disposable plastic cups.
Q 24.
What are the advantages of cloth bags over plastic bags during shopping?
Q 25.
Name two decomposers operating in our ecosystem. [All India 2011; Delhi]
Q 26.
Why is it necessary to manage our garbage?
Q 27.
What are the various steps of food chain called ?
Q 28.
A food chain represents a unidirectional flow of X. What is X ?
Q 29.
(a) Describe an activity to show that while paper is biodegradable but plastic (say, polythene) is non-
biodegradable.
(b) Explain why, some materials are biodegradable but some are non-biodegradable.
Q 30.
(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 31.
(a) Define an ecosystem. Give examples of any two ecosystems.
(b) List the biotic and abiotic components of an ecosystem.
Q 32.
Which radiations are absorbed by ozone layer ?
Q 33.
Explain how, harmful ultraviolet radiations of sunlight are prevented from reaching the earth’s surface.
Q 34.
‘If we excessively use pesticides to protect the crops from diseases, then it may cause long-term damage to mankind’. Justify this statement.
Q 35.
How can the wastes such as paper, plastic and metal objects be disposed of ?
Q 36.
Suggest any four activities in daily life which are eco-friendly.
Q 37.
Indicate the flow of energy in an ecosystem. Why is it unidirectional ? Justify.
Q 38.
How is the increase in demand for energy affecting our environment adversely?
Q 39.
Why are bacteria and fungi called decomposers? List any two advantages of decomposers to the environment. [Delhi]
Q 40.
What will happen if we kill all the organisms in one trophic level? [Delhi]
Q 41.
What is the important function of presence of ozone in earth’s atmosphere? [Delhi]
Q 42.
What is a food chain?
Q 43.
Which of the following belong to the same trophic level ?
Tree ; Frog ; Snake ; Grass ; Lizard
Q 44.
What will be the consequence of the absence of decomposers in the ecosystem ?
Q 45.
Name two predators of snakes in a food web operating in a forest ecosystem.
Q 46.
Name the various modes of waste disposal.
Q 47.
How are most of the solid wastes in urban areas disposed of ?
Q 48.
Why is improper disposal of waste a curse to environment?
Q 49.
Why are crop fields known as artificial ecosystems?
Q 50.
What are the two main components of our environment? [Delhi]
