Biology

Environment

Question:

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

Answer:

The advantages of using disposable paper cups over disposable plastic cups are:

  1. Paper cups are biodegradable. So, even if paper cups are thrown away after use, they will decompose (break down) automatically by the action of micro-organisms in due course of time. On the other hand, plastic cups are non-biodegradable. They will remain as such and pollute the environment.
  2. Paper cups can be disposed off by burning without causing much air pollution. On the other hand, burning of plastic cups produces toxic gases (poisonous gases) which causes too much air pollution.
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Environment

Q 1.

Why is the ozone layer loss more in cold regions?

Q 2.

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

Q 3.

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

Q 4.

What is a food chain?

Q 5.

Why is it necessary to manage our garbage?

Q 6.

Which of the following belong to the same trophic level ?
Tree ; Frog ; Snake ; Grass ; Lizard

Q 7.

A student went to study a local pond. In one part of the pond she noticed tadpoles scraping at some pond weed. In another part she saw a water beetle holding a tadpole in its jaws.A student went to study a local pond. In one part of the pond she noticed tadpoles scraping at some pond weed. In another part she saw a water beetle holding a tadpole in its jaws.
(a) Construct a food chain for the pond.
(b) How many links are there in this chain ?

Q 8.

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

Q 9.

Write the harmful effects of ozone depletion.

Q 10.

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

Q 11.

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

Q 12.

What are the various steps of food chain called ?

Q 13.

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 14.

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

Q 15.

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

Q 16.

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

Q 17.

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

Q 18.

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

Q 19.

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

Q 20.

Why are some substances non- biodegradable? [Foreign]

Q 21.

What is meant by bioconcentration of pesticides ? Which common pesticide has accumulated in human body in considerable amounts ?

Q 22.

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

Q 23.

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

Q 24.

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

Q 25.

What are the after effects of ozone depletion?

Q 26.

Why are plants called producers ?

Q 27.

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

Q 28.

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

Q 29.

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

Q 30.

Why is improper disposal of waste a curse to environment?

Q 31.

Name two natural ecosystems and two artificial ecosystems.

Q 32.

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

Q 33.

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

Q 34.

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

Q 35.

Which compounds are responsible for the depletion of ozone layer? [Delhi]

Q 36.

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.

Q 37.

Explain how harmful chemicals enter our bodies.

Q 38.

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

Q 39.

What is a food web?

Q 40.

Define ozone layer?

Q 41.

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

Q 42.

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

Q 43.

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)]

Q 44.

What step is being taken to limit the damage to the ozone layer? [Foreign]

Q 45.

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 46.

Name the organisms belonging to the second and the fourth trophic levels in the food chain comprising the following :
Frogs, Plants, Snakes, Hawk, Insects

Q 47.

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.

Q 48.

Where does all the energy in living organisms originate from ?

Q 49.

Why are there rarely more than five links (or five organisms) in a food chain ?

Q 50.

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