Environment (वातावरण): –The surrounding in which organism grow is called their environment.
The food habits, behaviour and body features of animals help them to live in different types of environments.
Habitat (आवास): – The place where an animal lives naturally is called habitat.
Habitat provides air, water, food and shelter to an animal.
The home of animals is found in the habitat.
Adaptation (अनुकूलन): –The changes in the feature or behaviour of an organism that help it to survive in its habitat are called adaptation.
The different types of habitats are-
Desert, Forest, Fresh water, Ocean, Polar regions, Mountains
Body covering
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Feathers in Birds
The body of birds is covered with feathers.
The flight feathers help the birds to fly.
The tail feathers help the bird to change direction and balancing.
The down feathers and the body feathers are close to the body and keep the bird warm.
Scales in Fish – The outer covering of body of fish is called scales.
Scales overlap one another to provide protection and form a water proof covering on the body.
The body of reptiles like lizard, crocodile and snake is covered with dry and rough scales which provide protection.
Snakes periodically shed their old skin and replace it with a new one. This is called moulting.
Shells – The body of aquatic animals is cover by a hard layer is called shells.
Ex- Turtles, tortoise, Snail, crab, lobster and oyster etc.
Shells help the animals to protect their soft body.
It acts like armour (kavach) that protects them from their predators (parbhakshi/shikari).
Fur and hair
The body of mammals is covered with hair.
Mammals are animals that have mammary glands.
They are warm blooded animals.
The hair traps heat and helps in keeping the body temperature constant.
Dense hair is called fur.
Animals with thick fur are generally found in very cold countries.
Some examples are the polar bear, yak and sheep.
Breathing in animals (जानवरों में श्वसन)
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All animals breathe in air to get oxygen and breathe out carbon dioxide.
Oxygen burns the food and breaks it to release energy, carbon dioxide and water vapour.
This energy helps the animal to live and perform all its functions.
The process in which oxygen (O2) burns the food and breaks it to release energy, carbon dioxide (CO2) and water vapour is called respiration.
Gills: –The special organs in aquatic animal which contain blood vessels are called Gills.
When water passes through the gills an exchange of gases takes place.
Oxygen is absorbed by the blood and carbon dioxide is given out.
Spiracles: – Insects have small openings on the sides of their bodies are called spiracles.
Exchange of gases takes place through these spiracles in insects.
Lungs:
Animals like reptiles, birds, human and mammals have a well-developed respiratory system.
They breathe through their nose.
The air reaches the lungs through the windpipe.
Lungs are the respiratory organs.
Haemoglobin – An important pigment found in blood which carries oxygen and gives blood its red colour is called Haemoglobin
The blood of insects does not contain haemoglobin and hence appears white not red.
Aquatic mammals like dolphin and whale also breathe through lungs.
They come up to the water surface to take in oxygen from the air.
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Feeding/Eating habits in animals
Animals need food for energy and growth.
Their eating habits depend on the type of food they eat.
Their mouth parts are suitably modified.
Herbivores: – Those animals that eat only plants or plant products are called herbivores.
Ex- cow, goat, buffalo, horse, deer, bison and giraffe
Carnivores: – Those animals that eat the flesh of other animals are called carnivores.
Ex- Tiger, lion, cat and dog.
Omnivores: –Those animals that eat both plants and flesh of animals are called omnivores. Ex-man, crow and bear
Rodents – Those animals that gnaw the seeds and fruits are called rodents.
Ex- rat, mice and squirrel
Reptiles: – Those creatures which crawl on ground are called reptiles.
Animals like snake, lizard and chameleon swallow their food as a whole and digest it slowly.
Birds: – Those creatures which have wings to fly are called birds.
Birds use their beaks to peck at their food.
Their beaks are modified in different ways to catch the food, they eat.
Insects: – Those creatures which have six legs are called insects.
Butterflies and bees use the food tube or proboscis to suck nectar from flowers.
Mosquitoes bite with the help of their proboscis and suck the blood of their victim.
Movement in animals
Animals need to move in the search of food and shelter to protect themselves and their young ones. Most animals move using their forelimbs and hind limbs.
Organs of Movement
Movement in aquatic animals
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Aquatic animals like fishes move with the help of their fins and tails.
The fins help to move forward and maintain balance while the tail helps to change direction.
Frogs and ducks have webbed feet to swim in water.
Turtles have flippers to swim.
Whales, seals and dolphins also use flippers to swim.
Penguin’s swim using their forelimbs which have developed into flippers and hindlimbs which have webbed toes.
Movement in aerial animals (live maximum time in air)
Aerial animals use their wings to fly in air and legs to crawl or hop on land.
Some insects like butterflies, mosquitoes and flies have wings that help them fly.
Some insects like lice, bugs, termites don’t have wings they move by crawling.
Birds – Those creatures which have wings to fly are called birds.
Birds have wings to fly.
The forelimbs are modified as wings.
The wings have feathers on them, which are attached to strong chest muscles.
Bird’s tail helps them to balance.
Birds use their legs to hop, walk, run and perch.
Birds use their hind legs for walking, hopping and perching.
Bird has light, hollow bones which make their body light.
Those birds which can’t fly are called flightless birds.
Ex- ostrich, kiwi and emu
Reptiles – Those animals which crawl on ground are called reptiles.
Reptiles like lizard, crocodile, and turtle have short limbs which help them crawl.
Snakes do not have limbs; they crawl and slither using the scales present on the lower side of their bodies.
Mammals – Those animals which nourish their young with milk are called mammals.
Mammals have well developed limbs.
Mammals like cows, camels, dogs use their four limbs for walking and running.
Human beings have two limbs (hind limbs) for walking
Migration of animals
The periodic movement of animals over large distances in response to seasonal changes is called migration
Animals move in search of food and shelter.
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