The Living Organisms and Their Surroundings

Have you observed differences among living organisms found in mountain areas, deserts or near coastal regions? 

You might have observed many kinds of trees on mountains (e.g. Himalays) — oaks, pines and deodars, very different from the ones on the plains. You might have also seen Camels and cactus plants, if you have travelled to deserts in Rajasthan. Sea Beach near Pune is full of casuarina trees.

All these places are so different from one another, some are cold, some very hot and dry, and some places so humid. And yet all of them have many organisms (living creatures) of various kinds.

Organisms and The Surroundings Where They Live

The deserts have camels, the mountains had goats and yak. Puri have some other creatures — crabs on the beach and such a variety of fish being caught by the fishermen at the sea! And then, there did seem to be some creatures like ants that are present in all these different locations. 

The kinds of plants found in each of these regions are so different from the plants of the other regions.

Habitat and Adaptation 

In the sea, plants and animals are surrounded by saline (salty) water. Most of them use the air dissolved in water. 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. The sea and the desert are very different surroundings and we find very different kind of plants and animals in these two regions.

Let us look at two very different kinds of organisms from the desert and the sea – a camel and a fish. 

Camel:
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.

Fish:

There are so many kinds of fish, but, do you see that they all have something common about their shape? All the ones shown here have the streamlined shape. This shape 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. That 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.

We see that the features of a fish help it to live inside water and the features of a camel help it to survive in a desert. We have taken only two examples from a very wide variety of animals and plants that live on the Earth. In all this variety of organisms, we will find that they have certain features that help them live in the surroundings in which they are normally found. 

The presence of specific features or certain habits, which enable a plant or an animal to live in its surroundings, is called adaptation. 

Different animals are adapted to their surroundings in different ways. The surroundings where organisms live is called a habitat. The organisms depend for their food, water, air, shelter and other needs on their habitat. Habitat means a dwelling place (a home). Several kinds of plants and animals may share the same habitat.

The plants and animals that live on land are said to live in terrestrial habitats. Some examples of terrestrial habitats are forests, grasslands, deserts, coastal and mountain regions. On the other hand, 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. 

There are large variations in forests, grasslands, deserts, coastal and mountain regions located in different parts of the world. This is true for all aquatic habitats as well.

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.

Abiotic factors like air, water, light and heat are very important for growth of plants. In fact, these abiotic factors are important for all living organisms.

Adaptation does not take place in a short time. Over thousands of years, the abiotic factors of a region change. Those animals which cannot adapt to these changes die out, and only the adapted ones survive.


Do You Know This?

There are some changes that can happen in an organism over a short period of time to help them adjust to some changes in their surroundings. For instance, if we live in the plains and suddenly go to high mountain regions, we may experience difficulty in breathing and doing physical exercise for some days. We need to breathe faster when we are on high mountains. After some days, our body adjusts to the changed conditions on the high mountain. 

Such 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. These changes are different from the adaptations that take place over thousands of years.

A Journey Through Different Habitats

Some Terrestrial Habitats

1. Deserts

There are desert animals like rats and snakes, which do not have the long legs that the camel has. 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.

Desert plants lose very little water through transpiration. The leaves in desert plants are either absent, very small, or they are present in the shape of spines. This helps in reducing loss of water from the leaves through transpiration. The leaf-like structure you see in a cactus is, in fact, its stem. 

Photosynthesis in these plants is usually carried out by the stems. The stem is also covered with a thick waxy layer, which helps to retain water. Most desert plants have roots that go very deep into the soil for absorbing water.

2. Mountain regions

Trees found 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.

Animals living in the mountain regions are also adapted to the conditions there. They have thick skin or fur to protect them from cold. For example, yaks have long hair to keep them warm. Snow leopard has thick fur on its body including feet and toes. This protects its feet from the cold when it walks on the snow. The mountain goat has strong hooves for running up the rocky slopes of the mountains.

3. Grasslands

A lion lives in a forest or a grassland and is a strong animal that can hunt and kill animals like deer. It is light brown in colour. Look at the picture of a lion and that of a deer (below). How are the eyes placed in the face for these two animals? Are they in the front or on the side of the face? Lions have long claws in their front legs that can be withdrawn inside the toes. 

It’s light brown colour helps it to hide in dry grasslands when it hunts for prey (animals to eat). The eyes in front of the face allow it to have a correct idea about the location of its prey. It has strong teeth for chewing hard plant stems of the forest.

A deer needs to know about the presence of predators ( animals like lion that make it their prey ) in order to run away from them and not become their prey. It has long ears to hear movements of predators. The eyes on the side of its head allow it to look in all directions for danger. The speed of the deer helps them to run away from the predators.

Some Aquatic Habitats

1. Oceans

Sea animals like squids and octopus, which do not have this streamlined shape. They stay deeper in

the ocean, near the seabed and catch any prey that moves towards them.

There are some sea animals like deer dolphins and whales that do not have gills. They breathe in air through nostrils or blowholes that are located on the upper parts of their heads. This allows them to breathe in air when they swim near the surface of water. They can stay inside the water for a long time without breathing. They come out to the surface from time to time, to breathe in air.

2. Ponds and lakes

In aquatic plants, roots are much reduced in size and their main function is to hold the plant in place. The stems of these plants are long, hollow and light. The stems grow up to the surface of water while the leaves and flowers, float on the surface of the water.

Some aquatic plants are totally submerged in water. All parts of such plants grow under water. Some of these plants have narrow and thin ribbon-like leaves. These can bend in the flowing water. In some submerged plants, leaves are often highly divided, through which the water can easily flow without damaging them. 

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.

Living Thing Around Us

Do all living things respire?

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. The process of breathing in animals like cows, buffaloes, dogs or cats is similar to humans. Respiration is necessary for all living organisms. It is through respiration that the body finally obtains energy from the food it takes.

Some animals may have different mechanisms for the exchange of gases, which is a part of the respiration process. For example, earthworms breathe through their skin. Fish, we have learnt, have gills for using oxygen dissolved in water. The gills absorb oxygen from the air dissolved in water. 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.

We learnt that in sunlight, plants use carbon dioxide of air to produce their own food and give out oxygen. Plants produce their food only during the daytime whereas respiration in them takes place day and night. The amount of oxygen released in the process of food preparation by plants is much more than the oxygen they use in respiration.

Do all living things respond to stimuli?

Yes! Almost all living things respond to stimuli. Changes in our surroundings that makes us respond to them, are called stimuli. In some plants like mimosa, commonly known as ‘touch-me-not’, leaves close or fold when someone touches them.

Living organisms and excretion

The process of getting rid of the wastes by the living organisms is known as excretion. Some plants find it possible to store the waste products within their parts in a way that they do not harm the plant as a whole. Some plants remove waste products as secretions.

Do all living things reproduce their own kind?

Animals reproduce their own kind. The mode of reproduction may be different, in different animals. Some animals produce their young ones through eggs. Some animals give birth to the young ones.

Plants also reproduce. Like animals, plants also differ in their mode of reproduction. Many plants reproduce through seeds. Plants produce seeds, which can germinate and grow into new plants. Some plants also reproduce through parts other than seeds. For example, a part of a potato with a bud, grows into a new plant. Plants also reproduce through cuttings. 

Living things produce more of their own kind through reproduction. It takes place in many different ways, for different organisms.

There is such a variety of living organisms, but, all of them show some common characteristics, as we have discussed. Yet another common characteristic is that living beings die. Because organisms die, organism types can survive over thousands of years only if they reproduce their own kind. One single organism may die without ever reproducing, but, the type of organism can exist only if there is reproduction. 

We see that, all living things seem to have some common characteristics. They all need food, respire, respond to stimuli, reproduce, show movement, grow and die. 

“What then is life?”

We see that respiration is a process that takes place in seeds even when some of the other life processes may not be very active. It may not be very easy to answer our question — “what then is life”?  However, looking at all the diversity of living beings around us, we can conclude that “life is beautiful”!