Our environment Worksheet-9
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What are functions of an ecosystem?
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Name the main components of an ecosystem.
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What do you call a functional unit, comprising of living and non-living components?
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Give two examples of man-made ecosystems.
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Why do all food chains start with plants?
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Give an example of a food chain that is the shortest.
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Give an example of an organism that acts and prey as well as predator in a food chain.
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Give two examples of organisms that generally occupy the top carnivore level.
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What are phytoplanktons?
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What are zooplanktons?
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Can an organism occupy position in more than one food chain? If so, give an example.
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Give proper term for each of the following :
(a) Smaller constituent operations unit of biosphere.
(b) Accumulation of non-biodegradable toxic substance in the increasing order in food chain.
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How is ozone layer formed?
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Which radiation is absorbed by ozone?
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Write the harmful effects of the ultraviolet rays.
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In which zone of atmosphere, ozone layer is present?
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What would happen if ozone layer in the atmosphere disappears?
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How does the ozone layer protect us from the harmful effects of the environment?
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What destructive effects do the chlorofluorocarbons bring about in the atmosphere?
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Name any two environmental problems caused by the various activities of human beings.
Answer:
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(i) It draws nutrient from soil, air and water,
(ii) It fixes solar energy.
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Lithosphere, hydrosphere, atmosphere, biotic and abiotic components.
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Ecosystem.
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Aquarium, Wildlife sanctuary.
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Only plants can transform light energy into chemical energy by photosynthesis and produce food.
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Plants → Man.
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Frog is the prey and predator of insect in a food chain.
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Vulture and Kite.
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The aquatic plants which are photosynthetic microscopic, free floating and form producers in the aquatic ecosystem are called phytoplanktons.
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The aquatic animals which are microscopic, free floating and depend upon phytoplanktons for their food are zooplanktons.
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Yes.
For example, snake can occupy third and fourth trophic levels in different food chains:
(i) Plants → Insects → Frogs → Snakes
(ii) Plants → Mice → Snakes.
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(a) Ecosystem (b) Biological magnification.
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Ozone is formed by the action of sunlight on oxygen of the air in the upper atmosphere, starting
at a height of about 16 km
The concentration of ozone is maximum at a height of about 23 km. This blanket of ozone around the earth is called ozone layer.
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Ultraviolet radiation.
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Harmful effects of UV rays are cataract, inflammatory diseases, cancer, etc.
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Stratosphere.
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Ultraviolet radiation would reach the earth and cause skin cancer and other problems.
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Ozone layer absorbs the harmful ultraviolet (UV) radiation of sunlight and thus protects us.
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Chlorofluorocarbons cause depletion of ozone layer.
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Our activities pollute the environment in various ways and some of the environmental problems are depletion of ozone layer and disposal of waste.