Topic outline

    • The Living Organisms and Their surroundings

      Q22. What do cockroaches do when we switch on the kitchen light at night?

      Ans. Cockroaches begin to move to their hiding places if the light in the kitchen is switched on at night.


      Q23. Is the process of breathing in animals like cows, buffaloes, dogs or cats similar to humans?

      Ans. Yes, the process of breathing in animals like cows, buffaloes, dogs or cats is similar to humans.


      Q24. What happens when someone touches ‘touch me not’ plants?

      Ans. In Mimosa plant, commonly known as ‘touch-me-not’, leaves close or fold when someone touches them.


      Q25. Name some animal which produces their young ones through eggs.

      Ans. Some animals which produce their young ones through eggs are birds, snake, turtle, tortoise, crocodile, lizard, fish, spider etc.

      Q26. Why do the plants move towards the sunlight?

      Ans. Plants grow towards sources of light because they need sunlight to be able to generate energy by photosynthesis.


      Q27. How particular types of organisms can survive over thousands of years?

      Ans. As organisms die, organism types can survive over thousands of years only if they reproduce their own kind.


      Q28. How do fish respire?

      Ans. Fish, have gills for using oxygen dissolved in water. The gills absorb oxygen from the air dissolved in water.

      Q29. Do plants also respire?

      Ans. Yes, exchange of gases in plants mainly takes place through their leaves. The leaves take in air through tiny pores in them and use the oxygen. They give out carbon dioxide to the air.


      Q30. All living things need food. Why?

      Ans. All living things need food because food gives organisms the energy needed for them to grow. Organisms also need this energy for other life processes that go on inside them.

      Q31. Why is excretion important in living organisms?

      Ans. Excretion is important in living organisms because undigested food and some wastes produced in other life processes have to be removed by the body.


      Q32. Why do desert animals like rats and snakes stay in burrow during day time?

      Ans. To stay away from the intense heat during the day, they stay in burrows deep in the sand. These animals come out only during the night, when it is cooler.


      Q33. Why it is warm inside a sack of wheat?

      Ans. It is warm inside a sack of wheat because there is some heat being produced inside the sack of wheat. The seeds respire and in that process give out some heat.


      Q34. Is there something different in the movements of non-living beings from the movements of living beings?

      Ans. Living beings moves on their own whereas non-living beings do not move on their own. Non-living beings are only moved with the help of an outside force.


      Q35. Is seed a living being?

      Ans. Though seed do not exhibit all the characteristics of living beings but still it is considered as living being because seed is the embryo of a new plant and grows into new plant when we plant it in soil and water it.


      Q36. What is acclimatisation?

      Ans. Small changes that take place in the body of a single organism over short periods, to overcome small problems due to changes in the surroundings, are called acclimatisation.