The World of Living Test - 4

This is the correct answer. Fish has a streamlined body, i.e. it tapers at the two ends, which helps the fish to swim.

This is the correct option. The skeleton in shark is made entirely of cartilage. Cartilage is a strong and durable material, but also lightweight and relatively flexible. These characteristics aid in the general movements of the shark in a variety of ways.

This is the correct answer. The body of the snail is covered by a shell. The outer skeleton of the snail, the shell, is made of calcium carbonate. The role of this shell is to provide protection.

Penguins are flightless birds. The movements shown by them on land are waddling and walking. In water, they swim efficiently.

Skeletal system provides framework to the body. Cartilages are not very hard and are present in the parts where movement is required. Ligament is the fibrous tissue joining two bones. Joints are the parts which allow the movement between particular body parts. It is the bones which are the hardest substance. They are made of calcium salts and provide framework to the body.

Habitat of animals and plants in different regions depends upon their body structure and its adaptability. For example, animals like yak, lions and ants live on ground and are known as terrestrial animals. Forests, grounds, grasslands and deserts are all included in the terrestrial habitat, whereas ponds, lakes, rivers, sea and ocean in the aquatic habitat.

Different kinds of plants are found in different regions because of the reason that survival of different plants in a particular area depends upon many factors like climate, soil texture, organisms found over there, etc. All these factors are collectively divided into two major categories; the living components are called biotic and the non-living components are called abiotic components. Thus, sunlight and air are the abiotic components.

Different places are having different climatic conditions and thus variety of flora and fauna. For example, terrestrial habitat refers to grounds, grasslands, etc. Arboreal refers to staying on trees like monkeys. Xeric refers to deserts having hot and dry climatic conditions and aquatic refers to water bodies.

Xerophytes are the plants growing in hot and dry places. For example, cactus is a plant that grows in deserts. Thus, to avoid the loss of excess water through stomata, its leaves are reduced to spine-like structures and it is the stem in these plants, which is green in colour and performs the functions of photosynthesis. Also, their stem is thick and waxy to prevent the loss of water.

Yak and cow are the terrestrial animals. Hydrilla and fish are the aquatic organisms. So, it is cactus, babool and camel which are the organisms belonging to deserts.