Why are green plants called ‘producers’? [All India]
Green plants are called ‘producers’ because they can produce food by photosynthesis in the presence of sunlight.
Give a method for the disposal of household wastes such as left-over food, fruit and vegetable peels, and leaves of potted plants.
(a) Define decomposers. Name one decomposer.
(b) What is the role of decomposers in the ecosystem ?
How does a biodegradable waste differ from a non-biodegradable waste ? Give two examples of non- biodegradable wastes which pollute our environment.
Name the phenomenon in which non-biodegradable chemicals get accumulated progressively at each trophic level of a food chain.
What name has been given to those organisms which break down the complex organic compounds present in dead animals and plants ?
What is the functional unit of the environment comprising of the living and non-living components called ?
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 ?
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 ]
Which of the following belong to the same trophic level ?
Tree ; Frog ; Snake ; Grass ; Lizard
Give an example to illustrate that indiscriminate use of pesticides may result-in the degradation of the environment. [All India]
Explain the terms ‘producer’ and ‘consumer’. Give two examples of producers and two of consumers.
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
(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.
Explain how, harmful ultraviolet radiations of sunlight are prevented from reaching the earth’s surface.
‘If we excessively use pesticides to protect the crops from diseases, then it may cause long-term damage to mankind’. Justify this statement.
Which disease is caused in human beings due to depletion of ozone layer in the atmosphere? [Foreign]
State two problems caused by the non- biodegradable waste that we generate in our daily life. [All India (C)]
Which class of chemicals is linked to the decrease in the amount of ozone in the upper atmosphere of the earth? [Delhi]
Name the organisms belonging to the second and the fourth trophic levels in the food chain comprising the following :
Frogs, Plants, Snakes, Hawk, Insects
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 ?
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 ?
Describe how decomposers facilitate recycling of matter in order to maintain balance in the ecosystem. [Foreign]
Why did United Nations act to control the production of chlorofluorocarbons (CFCs) used in refrigerators? [Delhi]