2.9 ADAPTATION
Living things are everywhere. Many animals and plants live on top of the ground as we do. But some live under the ground and even in the soil. Others live in ponds, rivers and lakes. The sea is full of living things and so is the air. Organisms live even in the hottest and coldest and driest places on Earth.
The kind of place where any organism lives is called its habitat. Water is the habitat of fish and trees are the habitat of monkeys. Every organism has to be fit for its own habitat. A fish cannot live in trees and monkeys cannot live under the water! The ways in which different organisms vary, so that they can live in different ways, in different habitats, are called adaptations. A fish is adapted to living in water. It has gills, which enable it to breathe under water, and fins for swimming. The gills and the fins are two of its adaptations. They help to make the fish fit for its watery way of life. Every living organism is adapted to its own special habitat and way of life.
Some adaptations in plants. The funny looking tree on the right is called a baobab. Some people say it was planted upside down! The baobab grows in parts of Africa where rainfall is uncertain. It stores water in its huge trunk and fat branches. This enables it to survive a long drought. We can say that its fat shape adapts it for the climate. A baobab tree
All plants need sunlight for making their food (by photosynthesis). They are adapted to expose their leaves to the sun in different ways. Trees have long trunks and branches that push their leaves high up towards the light. The stems of vines have special roots, suckers or tendrils. These adapt them so they can climb over other plants to reach the sunlight. Plants such as grasses and creepers are adapted to catch sunlight by spreading out and covering large areas of ground.
Some adaptations in birds. Birds provide some good examples of adaptation. They are adapted for flying in several ways. Compared to other vertebrates, their bodies are very light. They have wings instead of front legs, and very big chest muscles for flapping them. These muscles are the breast meat we enjoy when we eat roast chicken!
The beaks of different birds are adapted for eating different kinds of food. Look at the drawings and decide what each bird eats. The eagle is a carnivore. It has a strong, hooked beak for tearing flesh. The parrot has a powerful beak for cracking nuts. The kingfisher uses its long, sharp beak to spear small animals or fish. The honeyeater drinks nectar from flowers with its long thin beak. The duck's broad beak is adapted for pulling up weeds from the bottom of ponds or streams. And the mynah bird, which eats many different kinds of food, has a medium sized, all purpose beak.
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· 1. What do we mean by (i) habitat, (ii) adaptation?
· 2. How are (i) fish adapted for living in water, (ii) birds adapted for flying and feeding, (iii) monkeys adapted for living in trees?
· 3. Think about any different birds you know. How are their feet adapted for the different ways in which they use them?
· 4. Say how one plant and one animal you know are adapted to their habitats and ways of life.
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