Topic outline

    • The Living Organisms and Their surroundings

      Q37. How do plants reproduce?

      Ans. Most of the plants reproduce through the seeds. Seeds are sown in the soil which on germination grows into new plants. Some plants can reproduce through their stems, roots, leaves or cuttings.


      Q38. How are trees adapted to the conditions prevailing in mountain region?

      Ans. Trees in mountain regions are normally cone shaped and have sloping branches. The leaves of some of these trees are needle-like. This helps the rainwater and snow to slide off easily.

      Q39. What is respiration?

      Ans. Breathing is part of a process called respiration. In respiration, some of the oxygen of the air we breathe in is used by the living body. We breathe out the carbon dioxide produced in this process.

      Q40. Write a note on terrestrial habitats.

      Ans. The habitats of plants and animals that live on land are terrestrial habitats. Some examples of terrestrial habitats are forests, grasslands, deserts, coastal and mountain regions.

      Q41. Write a short note on aquatic habitats.

      Ans. The habitats of plants and animals that live in water are called aquatic habitats. Ponds, swamps, lakes, rivers and oceans are some examples of aquatic habitats.


      Q42. Differentiate between biotic and abiotic components.

      Ans. Difference between biotic and abiotic components

      Biotic Components

      Abiotic Components

      The living things such as plants and animals, in a habitat, are its biotic components.

      Various non-living things such as rocks, soil, air and water in the habitat constitute its abiotic components. Sunlight and heat also form abiotic components of the habitat.


      Q43. How frog is adapted to live both on land and in water?

      Ans. Frogs usually have ponds as their habitat. Frogs can stay both inside the pond water as well as move on land. They have strong back legs that help them in leaping and catching their prey. They have webbed feet which help them swim in water.

      Q44. Do plants also respond to stimuli?

      Ans. Yes, plants also respond to stimuli. Flowers of some plants bloom only at night. In some plants flowers close after sunset. In some plants like mimosa, commonly known as ‘touch-me-not’, leaves close or fold when someone touches them.


      Q45. How roots of terrestrial plants differ from aquatic plants?

      Ans. Some aquatic plants have their roots fixed in the soil below the water. In terrestrial plants, roots normally play a very important role in the absorption of nutrients and water from the soil. However, in aquatic plants, roots are much reduced in size and their main function is to hold the plant in place.


      Q46. What are the surroundings like, in the sea and the desert?

      Ans. Sea - In the sea, plants and animals are surrounded by saline (salty) water. Most of them use the air dissolved in water.

      Desert - There is very little water available in the desert. It is very hot in the day time and very cold at night in the desert. The animals and plants of the desert live on the desert soil and breathe air from the surroundings.


      Q47. What are the adaptations that allow fish to live in water?

      Ans. Fish have the streamlined shape that helps them move inside water. Fish have slippery scales on their bodies. These scales protect the fish and also help in easy movement through water. Fish have flat fins and tails that help them to change directions and keep their body balance in water. Gills present in the fish help them to use oxygen dissolved in water.


      Q48. What are the adaptations that help a camel to survive in desert?

      Ans. The body structure of a camel helps it to survive in desert conditions.

      Camels have long legs which help to keep their bodies away from the heat of the sand. They excrete small amount of urine, their dung is dry and they do not sweat. Since camels lose very little water from their bodies, they can live for many days without water.