Biology

Environment

Question:

Explain ‘biological magnification’ with the help of an example. [All India]

Answer:

Pesticides used in crops are washed down .into the soil. From soil these are absorbed by plants along with water and minerals and thus, they enter the food chain. While consuming the crops, human beings also consume these pesticides which get accumulated in our bodies. This phenomenon is known as biological magnification.

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Environment

Q 1.

Write the harmful effects of ozone depletion.

Q 2.

Explain how harmful chemicals enter our bodies.

Q 3.

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

Q 4.

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

Q 5.

What is a food chain?

Q 6.

Why is it necessary to manage our garbage?

Q 7.

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 8.

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

Q 9.

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

Q 10.

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

Q 11.

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

Q 12.

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

Q 13.

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

Q 14.

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 15.

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

Q 16.

Write one or two words for each of the following statements/definitions :Write one or two words for each of the following statements/definitions :
(a) Each level of food chain where transfer of energy takes place
(b) The physical factors like temperature, rainfall, light, soil, air and water of an ecosystem
(c) Organisms which depend on the producers for food either directly or indirectly
(d) The physical and biological world where we live in
(e) Selfcontained unit of living things and their non-living environment needing only sunlight for its functioning

Q 17.

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

Q 18.

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

Q 19.

Why is improper disposal of waste a curse to environment?

Q 20.

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

Q 21.

Why are some substances non- biodegradable? [Foreign]

Q 22.

List two man-made ecosystems. [All India]

Q 23.

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

Q 24.

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

Q 25.

What is a food web?

Q 26.

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

Q 27.

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 28.

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

Q 29.

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

Q 30.

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 31.

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

Q 32.

Name the phenomenon in which non-biodegradable chemicals get accumulated progressively at each trophic level of a food chain.

Q 33.

Name two natural ecosystems and two artificial ecosystems.

Q 34.

Why are plants called producers ?

Q 35.

What are the various steps of food chain called ?

Q 36.

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

Q 37.

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

Q 38.

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 39.

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

Q 40.

Where does all the energy in living organisms originate from ?

Q 41.

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

Q 42.

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 43.

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

Q 44.

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

Q 45.

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

Q 46.

What are the after effects of ozone depletion?

Q 47.

What is the functional unit of the environment comprising of the living and non-living components called ?

Q 48.

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

Q 49.

What is the difference between the food habits of organisms belonging to the first and the third trophic levels ? Give one example each of the organisms belonging to these two trophic levels.

Q 50.

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→  …………….