Which category of organisms forms the starting point of a food chain ?
Producer.
Name the phenomenon in which non-biodegradable chemicals get accumulated progressively at each trophic level of a food chain.
(a) What is meant by biodegradable waste materials ? Give two examples of biodegradable wastes.
(b) Which of the following materials are non-biodegradable ?
Aluminium wire, Tea leaves, Synthetic fibre, Wool
Which of the following belong to the first trophic level of a food chain? Grass, Grasshopper, Plants, Rat, Tiger [Foreign]
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]
What is the functional unit of the environment comprising of the living and non-living components called ?
Explain how, harmful ultraviolet radiations of sunlight are prevented from reaching the earth’s surface.
Name the wastes which are generated in your house daily. What measures would you take for their disposal?
Why are bacteria and fungi called decomposers? List any two advantages of decomposers to the environment. [Delhi]
Which one of the following is not a terrestial ecosystem ?
Forest, Grassland, Aquarium, Desert
State whether the following statements are true or false :State whether the following statements are true or false :
(a) In biology, human beings are called producers.
(b) Secondary consumers and tertiary consumers, both are carnivores.
Which one term in the following includes the others ?
air, flora, fauna, environment, water, sunlight, soil
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]
Which class of chemicals is linked to the decrease in the amount of ozone in the upper atmosphere of the earth? [Delhi]
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 ?
If 5 joules of energy is available at producer level (plants), then how much energy will be transferred to the lion in the following food chain ? If 5 joules of energy is available at producer level (plants), then how much energy will be transferred to the lion in the following food chain ?
Plants —> Goat —> Lion
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 ]
Explain the terms ‘producer’ and ‘consumer’. Give two examples of producers and two of consumers.
(a) Define decomposers. Name one decomposer.
(b) What is the role of decomposers in the ecosystem ?
(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.
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