What would happen if the ozone layer in the atmosphere completely disappears ?
If the ozone layer in the atmosphere disappears completely, then all the extremely harmful ultraviolet radiations coming from the sun would reach the earth. These ultraviolet radiations would cause skin cancer and other ailments in men and animals, and also damage the plants.
Give a method for the disposal of household wastes such as left-over food, fruit and vegetable peels, and leaves of potted plants.
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 ?
Describe how decomposers facilitate recycling of matter in order to maintain balance in the ecosystem. [Foreign]
“Damage to the ozone layer is a cause for concern.” Justify this statement. Suggest any two steps to limit this damage. ‘ [Delhi]
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) Define decomposers. Name one decomposer.
(b) What is the role of decomposers in the ecosystem ?
Name the phenomenon in which non-biodegradable chemicals get accumulated progressively at each trophic level of a food chain.
What are the causes of depletion of ozone layer ? Which diseases are likely to be caused if the ozone layer will become thinner ?
‘If we excessively use pesticides to protect the crops from diseases, then it may cause long-term damage to mankind’. Justify this statement.
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]
Which of the following belong to the same trophic level ?
Goat; Spider ; Plants ; Hawk ; Rat .
Explain the terms ‘producer’ and ‘consumer’. Give two examples of producers and two of consumers.
State two problems caused by the non- biodegradable waste that we generate in our daily life. [All India (C)]
What is meant by bioconcentration of pesticides ? Which common pesticide has accumulated in human body in considerable amounts ?
(a) With the help of a flow diagram, describe how energy from the sun flows through various trophic levels.
(b) Explain why, the flow of energy in the ecosystem is said to be unidirectional.
Which disease is caused in human beings due to depletion of ozone layer in the atmosphere? [Foreign]
Which of the following belong to the same trophic level ?
Tree ; Frog ; Snake ; Grass ; Lizard
Fill in the following blanks with suitable words : Fill in the following blanks with suitable words :
(a) Decomposer organisms are……………. in their action.
(b) In nature, all green plants are……………. whereas animals are consumers.
(c) A series of organisms, each of which feeds on the next organism, the beginning of which is a green plant, is called a…………….
(d) The science that deals with the inter-relationships of living things with one another and their environment is called …………….
(e) Plastic is a……………. material whereas paper is a……………. material.
Consider the food chain :
Grass → Deer → Lion
What will happen if all the lions are removed from the above food chain ?
How does a biodegradable waste differ from a non-biodegradable waste ? Give two examples of non- biodegradable wastes which pollute our environment.
(a) What is meant by non-biodegradable waste materials ? Give two examples of non-biodegradable wastes.
(b) Which of the following materials are biodegradable ?Animal bones, Iron nails, Plastic mugs, Leather belts, Silver foil
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 ?
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→ …………….