Living Organisms And Their Surroundings: science class six
Types of Habitat
Habitat can be classified into following types:
(a) Terrestrial habitat
(b) Aquatic habitats
Terrestrial habitat
The plants and animals that live on land are said to live in terrestrial habitats. This means the habitat on land is called TERRESTRIAL HABITATS.
Since, conditions for living are the best on land, therefore, a large variety of organism is found on the land. This can range from marshy areas to barren deserts to snow capped mountains. Some examples of terrestrial habitats are forests, grasslands, deserts, coastal and mountain regions.
Type and number of biotic and abiotic component will always be differ from place to place.
Types of Terrestrial Habitat
Terrestrial habitat can be divided into following types
(a) Desert
(b) Rainforest
(c) Grassland
(d) Mountaineous region
Desert habitat
Because of little rain desert is hot and dry. Desert has very little vegetation. Because of little vegetation and hot and dry condition, especially large animal does not get proper shelter from the sun in desert.
Due to that most of the animals which survive in deserts are insects, birds, reptiles and other small mammals. Camel is the only big animal found in the desert. Camel is called the ship of the desert.
Small animals like rats and snakes have advantage because of their size. These small animals can stay in burrows deep in the sand during the daytime. They become active during the night when desert becomes cooler. This enables them to prevent the loss of water from their body. Animals which roam during night are called nocturnal animals. This explains how certain animals adapt to the climate in desert.
Adaptation in Camel
Camel has special types of characteristics. These characteristic of camels enable them to adapt in the desert.
Camel has long legs. Long legs of camels keep them away from the hot sand of the desert. Paws of camel are like a large pad, which enables them to move in hot and slippery sand of desert.
Camel has a large hump on its back. These hump is reservoir of food in the form of fat. Camel can drink a large amount of water. Camels 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.
Some animals, like lizard, snake go into long period of sleeping, which is called hibernation during the very cold situation.
Animals live in desert excrete less amount of water which enables them to cope up with the situation of scarcity of water.
Plants found in desert
There are many plants found in desert. Plants found in deserts are are called xerophytes (Xeros means dry and phyte means plant). Plant of cactus is an example of xerophytes. The leaves in cactus are modified into thorns. These thorns of cactus help in prevention of water loss.
The stem of cactus is modified into leaf like structures.
These leaf like structures are spongy and hence retain water. Because of these properties they can live in the deserts where there is a great scarcity of water. Plant, like plum (ber) and acacia (babool), which is found in desert, have segmented leaves to prevent the loss of water. Its root penetrates deep into soil to get water.
Rainforest
Rainforest is known as tropical rainforest. Rainforest is found near the tropical region. Because of the location near to equator, rainforest receives more sun shines as well as more rain. So, the climate of the rainforest is warm and humid. Because of availability of plenty of water and food, a large number of animals live in the rainforest, like, elephants, rhinoceros, tigers, lions, deer, sheep, goat, bears, monkeys, birds, snakes, frogs, and lizards etc.
Although a wide variety of food is available in the rainforest, but due to living of a large number animals there is lot of competition for food. Many animals, found in the rainforest, adapted to eat a particular type of food, which is not eaten by other animals. This enables them to get food easily. As for example parrots eat nuts. Parrot have strong curved beaks with the help of that it can crack open the tough shells of nuts. Parrot lives in holes in trees.
Monkeys adapted to live on trees. Monkeys have strong arms and two legs, which help them to swing from one tree to another. Monkeys have a long tail that help them to keep right direction while swinging from one tree to another. Sometimes monkey uses its tail to hand from tree.
Lion and Tigers found here are of brown colors. Tigers have black lines on their body. Tigers found in the rainforest have orange colour also. This type of color of the tiger and lion enables them to hide in the forest. This adaptation of matching of colour with surroundings is called CAMOUFLAGE.
Camouflage is useful for predators while catching prey that has not seen them. As for example orange with black stripes colour of tigers hide them easily in the forest, so that it can reach near the prey keeping him hidden.
Birds are adapted to live an arboreal life as well as to fly in air. The bones of birds are hollow to reduce weight. Their fore limbs are modified into wings. They eat frequently and expel waste product from body frequently in order to reduce weight. Their claws are well suited for perching on trees.
A large number of variety of trees found in the rain forest. As this type of region gets a huge amount of rainfall, so rainforest has very dense vegetation. Tall trees are found here. Leaves of these trees have grooves and special type of tip due to which water drip easily to the ground and not collected on the leaves. This dripping off of water easily prevents the leaves to get rotten.
A large variety of small plants are found in the lower level. They have large leaves so that they can absorb much sunlight for photosynthesis, as due to dense forest only small amount of sunlight reach at the lower level.
Grassland
Grassland is known as tropical savannah also. Grassland is found in hot climates having normal rainfall. Tall grass and small number trees are found here. Cheetah, lion, leopard, zebra, giraffe, deer etc are found here. Most of the animals of grassland are fast runner.
Lions and tiger found in grassland are of light brown colour which enables them to get hidden in the grass while catching prey. Tigers and lions have strong claws that can be withdrawn inside their toes, which helps them creep up to their prey without making a noise while catching the prey.
Deer are fast runner that helps to save his life from predators. Deer have long ears that enable them to hear the movements of predators. They have eyes on the side of their heads, which help them to see in the all directions for danger. They move in herds that also help them to protect from predators.
Adaptation similar to deer is found in some other animals also, like zebra, and bison etc.
Grass found in the grassland in plenty, this may be one of the cause of getting its name. Grass found in this region have flexible stalks so that they can bend and do not get broken in windy conditions. Grass has strong root to hold the soil that enables it to get not uprooted with fast wind.
Trees found in the grassland are of small size with small leaves. Its root goes deep into soil in search of water, and gives strong anchoring to the tree.
During the rainy season all animals live here survive comfortably but in the dry season they migrate to other places.
Mountain
Mountain habitat is generally very cold. Because of its high altitude cold wind blows here. During winter mountain gets covered with thick layer of snow.
Animals found in Mountain
There are a large variety of plants and animals live here. Leopard, bear, yak, sheep, goat etc are lived here. Animals found here are generally of white or light colour. The light colour skin helps the animals found here in thermal regulation.
Animals found in the mountainous region have thick skin. Some animals, like goat, yaks, leopard, sheep etc has thick fur or long hair on their body. This thick fur and thick skin act like insulator, which enables them to survive in the extreme cold. Bears found in this region have a thick layer of fat deposited under their skin.
This thick layer of fat deposited under the skin of animals found in the mountainous region acts as a insulator, which regulates the body temperature during extreme cold. You know that fat is the stored food deposited under the skin. This fat enables the animals found in the extreme cold region during the scarcity of food.
Trees found in Mountain
Trees found in the mountain region adapted to such condition. Pine and deodar trees are found in plenty in this region. It has cone shaped and sloping branches. Leaves of these trees has needle like shape. Because of this type of special conical shape of branches and leaves snow accumulated on it, slides off easily.
If trees, which found in mountain region do not have the conical shaped branches and leaves, then due to the accumulated load of snow, branches get broken that can destroy the trees.
Aquatic habitat
About 70% of earth is covered with water. Water is known as aquatic habitat. There are several animals and plants live in water. Fish are common that live in water. Apart from fish, animals, like crocodile, turtle, hippopotamus, snakes etc live in water. They are well adapted to live in water.
Fish have laterally compressed boat shaped body, which makes its body streamlined. This type of body reduces friction during swimming. Fish have fins and tails which help in keeping right direction while swimming.
Some fish have air bladder inside their body, which help them to get float in water.
Some sea animals, like squid and octopus do not have streamlined body like fish. However, when they move in water, their bodies get streamlined shape. Gills present in fish enable it to take breathe in and out under the water.
Some aquatic animals like dolphin and whale etc. have blowholes to breathe and no gills. Dolphin and whale have blowholes that located near the upper part of their heads. So, they have to come on the water surface to breathe. These blowholes enable whales and dolphins to breathe while swimming near the surface of water. They are adapted to stay inside the water without breathing for several minutes.
Frogs and duck has webbed feet that help them while swimming. Frog is called amphibians as it can stay in water as well as on the land. Frog has strong back legs, which help it in leaping and catching prey.
A large number of plants like lotus, water lily, and spirogyra etc found in water. The plants found in water are called hydrophytes. These may be free floating, rooted and floating or submerged. The stems of aquatic plants are long and narrow that keep them withstand with water current without getting damaged. Stems are hollow filled with air, which enable them to float. Submerged plants, like tape grass, have long and narrow leaves which enable them to survive in the current of water without getting damaged.
Some plants float on water, like lotus, water lily etc. Floating plants have large and flat leaves. Upper surface of leaves of a floating plants have waxy surface, which make them waterproof. Their stems are hollow filled with air, which enables them to withstand easily in water.
Summary
All the living organism needs a place to live in addition to food, water and air.
The place where an organism lives is called habitat.
Habitat means dwelling place (a home).
This special ability of survival of living beings in different conditions is called adaptation.
Adaptation is a long process of evolution.
It takes thousands of years to develop a particular adaptation.
Habitat can be divided in two category. One is Terrestrial habitat and second is aquatic habitat.
Terrestrial habitat further can be divided in four category. Deserts, Rainforest, Grassland and Mountainous region.
Animals and plants live in different type of habitats are of different types and they adapted with their place of dwelling.
Living being have following type of common characteristics:
(a) All living things need food
(b) All living things show growth
(c) All living things respire
(d) All living things respond to stimuli
(e) All living organisms do excretion
(f) All living things reproduce their own kind
(g) All living organism die
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