Why is the ozone layer loss more in cold regions?
Ozone loss is most severe in the world's coldest regions because of clouds in the stratosphere known as polar stratospheric clouds. They provide a surface on which the chemical reactions that result in the destruction of ozone takes place.
Describe how decomposers facilitate recycling of matter in order to maintain balance in the ecosystem. [Foreign]
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
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 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 ?
“Damage to the ozone layer is a cause for concern.” Justify this statement. Suggest any two steps to limit this damage. ‘ [Delhi]
‘If we excessively use pesticides to protect the crops from diseases, then it may cause long-term damage to mankind’. Justify this statement.
In a food chain consisting of grass, frog, bird and insects, where will the concentration of the harmful chemicals be maximum ?
State two problems caused by the non- biodegradable waste that we generate in our daily life. [All India (C)]
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) Define an ecosystem. Give examples of any two ecosystems.
(b) List the biotic and abiotic components of an ecosystem.
Why did United Nations act to control the production of chlorofluorocarbons (CFCs) used in refrigerators? [Delhi]
Give an example to illustrate that indiscriminate use of pesticides may result-in the degradation of the environment. [All India]
(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
Name the phenomenon in which non-biodegradable chemicals get accumulated progressively at each trophic level of a food chain.
What is the functional unit of the environment comprising of the living and non-living components called ?
What name has been given to those organisms which break down the complex organic compounds present in dead animals and plants ?