Class Notes NCERT Solutions for CBSE Students
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Question: What do you mean by the term ‘Migration’? Give an example of a living organism which show this phenomenon.
Answer: The regular seasonal journey undertaken by many species of animals and birds to escape the harsh and cold conditions of weather is known as migration. Many animals, birds and fishes migrate to warmer regions in winter and come back when winter is over. Migration is marked by its annual seasonality. For example, the Siberian crane that comes from Siberia migrates to India at places like Bharatpur in Rajasthan and Sultanpur in Haryana
Weather, Climate and Adaptations of Animals to Climate – Question: “All the changes in the weather are caused by sun.” Do you agree with this statement? If yes, then explain.
Answer: Yes, the sun is the primary source of energy that causes changes in the weather because sun is a huge sphere of hot gases at a very high temperature. The distance of the sun from us is very large. Even then, the energy sent out by the sun is so huge that it is the source of all heat and light on the earth.Energy absorbed and reflected by the earth’s surface, oceans and the atmosphere play important roles in determining the weather at any place. Weather varies from place to place. It is different in a desert, near coastal areas or near a mountain.
Question: What are adaptations? Explain the types of adaptations.
Answer: An adaptation is trait of an organism that has been favored by natural selection.
Adaptations are of following types:
- Structural adaptations are special body parts of an organism that help it to survive in its natural habitat (e.g., skin colour, shape, body covering).
- Behavioral adaptations are special ways of a particular organism that behaves to survive in its natural habitat.
- Physiological adaptations are systems present in an organism that allow it to perform certain biochemical reactions (e.g., making venom, being able to keep a constant body temperature).
