Page 82 - Viva ICSE Science 5 : E-book
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TIME TO REVISE
Fill in the blanks.
1. ___________ are the producers.
2. Decomposers like ___________ and ___________ feed on dead remains of plants and
animals.
3. In the absence of __________ soil would not get the nutrients required by the __________.
4. Animals breathe in ___________ and give out carbon dioxide which is needed by
___________.
Balance in Nature
Food chain and interdependence of living beings maintain a balance in nature. A
balance is necessary for the well-being and survival of all living things. Any change in
the food chain may disturb the balance. This will aff ect the survival of all living beings.
For example, killing many snakes can lead to a large increase in the population of rats, as
less of rats will be eaten. Increase in rat population may lead to large-scale destruction
of food crops. This, in turn, may lead to starvation and death.
Causes of Imbalance in Nature
Broadly, imbalance in nature may occur due to natural hazards or human activity.
Natural factors
The following are some natural factors that cause imbalance in nature.
Flood: It is the overfl ow of large amount of water in an area.
Too much of rain can cause fl ood in an area. This can cause
destruction of plants and animals on a large-scale.
Forest fi re: Forest fi re may be caused due to continued dry
condition and rising temperature. It may also be caused when
lightning strikes forest. Forest fi re kills many living beings in
the forest.
Droughts: Lack of rain for a long time may lead to drying of
water bodies. Such condition is known as drought. It may
cause plants and animals to die in mass scale.
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