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 ?
Cat.
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
Describe how decomposers facilitate recycling of matter in order to maintain balance in the ecosystem. [Foreign]
Which one of the following is not a terrestial ecosystem ?
Forest, Grassland, Aquarium, Desert
Name the wastes which are generated in your house daily. What measures would you take for their disposal?
Consider the food chain :
Grass → Deer → Lion
What will happen if all the lions are removed from the above food chain ?
State two problems caused by the non- biodegradable waste that we generate in our daily life. [All India (C)]
In a food chain consisting of grass, frog, bird and insects, where will the concentration of the harmful chemicals be maximum ?
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→ …………….
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
Why is ozone layer getting depleted at the higher levels of the atmosphere? [Delhi (C)]
Why did United Nations act to control the production of chlorofluorocarbons (CFCs) used in refrigerators? [Delhi]
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 first trophic level of a food chain? Grass, Grasshopper, Plants, Rat, Tiger [Foreign]
Name the organisms belonging to the second and the fourth trophic levels in the food chain comprising the following :
Frogs, Plants, Snakes, Hawk, Insects
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.
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 ?
(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.
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 ?
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 ?
Give a method for the disposal of household wastes such as left-over food, fruit and vegetable peels, and leaves of potted plants.
“Damage to the ozone layer is a cause for concern.” Justify this statement. Suggest any two steps to limit this damage. ‘ [Delhi]
Select two non-biodegradable substances from the following waste generated in a kitchen: spoilt food, paper bags, milk bags, vegetable peels, tin cans, used tea leaves. [Delhi]