Question 1 What are living things. Give examples?
Question 2 Give few differences between living and non-living things?
Question 3 What is respiration?
Question 4 Why is respiration essential for living organism?
Question 5 What is meant by term stimuli?
Question 6 Give few examples of growth?
Question 7 What is phototropic movement. Give example to explain the term?
Question 8 Give few examples to show that living things respond to stimuli?
Question 9 What happen if we move from dark rom to bright sunshine suddenly? Explain your answer in terms of response to stimuli?
Question 10 Give example of response of animals to stimulus?
Question 11 Give example of response of plants to stimulus?
Question 12 Define the term respiration?
Question 13 Define the term breathing?
Question 14 Explain how earthworm breathe through skin?
Question 15 Explain how fish breathe through gills?
Question 16 What is stomata. Explain its function?
Question 17 Name the important waste product of plants? How do plants get rid of these waste products?
Question 18 How are potato plants produced?
Question 19 Describe the cutting method of reproduction in plants?
Question 20 What do you understand by the term life span of a living thing?
The mountains of Himalaya are very cold places. The mountain areas have many kinds of trees like oaks, pines and deodars. The mountains have also unique animals like yak and mountain goat.
The desert area like in Rajasthan are very hot and dry. The desert areas have many special type of plants such as cactus and animals like camel.
The coastal areas are very humid and have an entirely different kind of trees such as palm trees.
Sea water contains yet another kind of animals like fish, crab etc.
The surroundings are so different from one another in climate but all of them have many living things in them. Moreover the kind of living things found in each of the surroundings are very different from the living things of the other surrounding.
Living things Around Us
Those things which need food, water and air for the survival are called living things.
For example: boy, girl, animals, birds, frog, fish, cockroach, lizard, squirrel, ant, insect, rat etc. All the plants also need food, water and air, so all the plans are also living things.
Characteristics of living things
The characteristics of living things are given below:
(1) Living things need food, air and water.
(2) Living things can grow.
(3) Living things can move by themselves.
(4) Living things can respond to stimuli.
(5) Living things respire.
(6) Living things excrete.
(7) Living things can reproduce. They can have young ones.
(8) Living things have a definite lifespan.
(9) Living things have a definite life span.
All the living things (plants and animals) need food to stay alive. They also need air and water. The plants make their own food by process of photosynthesis but animals obtain the food from plants or other animals.
Food gives the material for growth and energy to carry out various life processes taking place inside the living things. Non living things do not need food, air and water.
Growth means increase in size. The young ones of all the living things (plants and animals) grow and become bigger in size with the passing of time.
For Example : A seed grows and becomes a plant. A baby grows and becomes an adult. When living things grow, they become taller and bigger on there own. A small puppy grows and becomes a dog, a kitten grows and becomes a cat, a chicken hatched from an egg grows and become a hen or cock.
The growth in living things occurs by the division of the single cell to form a larger number of cells. As the living grows, the number of cells in its body go on increasing. Non-living things do not grow.
All the living things move by themselves. The animals and plants move in different ways. Animals can move from one place to another or they can move there body parts.
For Example : a frog moves when it jumps into a pond. A bird moves when it flies in the sky. Fish moves when it swims in water. Animals move from one place to another for food, protection from enemies and protection from natural disasters.
The plants are fixed in the soil at a place, so they cannot move like animals from place to place. The plants parts can move only parts of their body such as leaves, flowers, shoots and roots. The plant parts move towards a stimulus such as sunlight, water or gravity. The leaves and flower of a sunflower plant move by bending towards the sun to face the sunlight.
The movement of a part of the plant towards light is called phototropic movement.
Some flowers show movement by opening or closing their petals. The flowers of dandelion plant open up in the morning and close in the evening when the lights fades. In living things movement is caused by internal factors such as muscles pulling on bones, contraction and relaxation of only muscles or by the action of chemicals called hormones.
The movement in non-living things is caused by an external force such as push of our hand, blowing air or wind, flowing water or hot and compressed gases.
The movement of clouds is caused by the force of blowing air or wind. The logs of wood move in river by the force of flowing water. And a car or bus moves by the force of hot and compressed gases is produced by the burning of petrol or diesel in its engine.
Response to Stimuli
The changes in the surrounding to which living things respond are called stimuli. The living things show response to external stimuli such as heat, light, touch, sound, smell, taste, water and chemicals.
If a man touches a very hot object accidentally, he quickly pulls his hand away from the hot object. The stimulus is heat and the man responds by moving his hand away from the hot object.
If a barefooted man steps on a sharp object like thorn, he quickly pulls away his foot from the sharp object. The stimulus is pain and the man response by moving his foot away from the sharp object.
If we move from a dark place into bright sunshine suddenly our eyes shut themselves automatically for moment. Bright light is the stimulus and we respond by shutting the eyes momentarily.
Animals also respond to stimuli. When we move towards the bird, the bird flies away from us. In this case fear is the stimulus and the bird responds by moving away. Birds fly away when they hear a loud sound. In this case loud sound is the stimulus and the birds respond by moving away.
Some animals are attracted by light and hence go towards a source of light. Moths and certain beetles are attracted by light. We can see these moths and beetles flying around a street light at night, especially during rainy season. The stimulus is light and the moths and beetles respond by moving towards the source of light.
Wild animals run away when bright light is flashed towards them. Here also the stimulus is bright light and the wild animals respond by running away from it .
Plants also respond to changes around them or plants also respond to stimuli. Plants respond to stimuli such as touch, sunlight, gravity, water and chemical.
For Example: Mimosa plant which is commonly known as sensitive plant of touch me not plant. If we touch the leaves of a mimosa plant with our fingers, then its leaves fold up and droop . The touch of finger is the stimulus and the Mimosa plant response by folding its leaves.
If a potted plant is kept in the open space, the stem of plant grows straight up towards the source of life Sun. Keep the potted plant having straight stem near the window in a dark room so that sunlight falls on it from the right side only.
After some days we will see that the stem of plant bends towards the right size from where the light is coming. The stem of growing plant bends towards the light. The stimulus is sunlight and the plant responds by bending its stem towards it.
The flowers of some plants open up in the morning and bright light but close after sunset when it gets dark.
In some plants however, the flowers close during the daytime and bloom only at night. The petals of moon flower close during the day when there is bright light but open up at night When it is dark and there is no light. Non-living things do not respond to changes in their surroundings.
Respiration is the chemical process in which food taken by an organism combines with oxygen to release energy.
This energy is used by the organism to carry out its various life processes. Carbon dioxide and water are the other products of the process of respiration. The process of respiration takes place inside the body of the plant or animal.
Our body takes in oxygen from air for respiration. At the same time, it gives out carbon dioxide produced by respiration. This exchange of gases takes place in our lungs. The process of taking air into the lungs through nose and then expel it through nose is called breathing.
When we breathe in, the air moved from outside to the inside of our body. And when we breathe out, then the air moves from inside of our body to the outside . The purpose of breathing in air is to provide oxygen to our body for carrying out respiration.
In respiration, some of the oxygen of air we breathe in is used for producing energy from food and produce carbon dioxide as waste products. When we breathe out carbon dioxide produced during respiration is expelled from our body.
In animals a slow, up and down movement of their abdomen indicating that they are breathing.
The process of breathing or respiration involves exchange of gases. This is because during this process, oxygen is given to the body cells and carbon dioxide is removed. Animals have different mechanism for breathing.
The earthworm breathes through its skin. The skin of an earthworm is quite thin and moist, and has a good blood supply. So, the earthworm absorbs oxygen needed for respiration through its thin and moist skin. The carbon dioxide produced during respiration is also expelled from the body of the earthworm through its skin. In earthworm gaseous exchange takes place through it skin.
The fish has special organs of breathing called gills. The gills absorb oxygen dissolved in water. The fish breathes by taking in water through its mouth sending it over the gills. When water passes over the gills, the gills extract dissolved oxygen from this water. This oxygen is used for respiration in the fish. The carbon dioxide produced during respiration is also expelled by the gills into the surrounding water. The fish has no lungs like us, the gaseous exchange in fish takes place in the gills.
Plants also need energy. The plants get this energy by the process of respiration. The plants use oxygen for respiration and release carbon dioxide in the process. Every leaf of a plant has a large number of tiny pores or holes called stomata on it surface. The oxygen enters the plant leaves through stomata and utilised in respiration. The carbon dioxide produced during respiration inside the plant is also expelled from the leaves through stomata. The exchange of gases in plants during respiration takes place through the tiny pores in their leaves called stomata.
During daytime, when sunlight is available, the plants use carbon dioxide from air to make their own food by photosynthesis and release oxygen gas into the air. The amount of oxygen produced by plants during photosynthesis in daytime is, much more than oxygen they use in respiration. Photosynthesis in plants takes place only during daytime when sunlight is available but respiration in plants takes place during daytime as well as at night time.
The living things use food to obtain energy by the process of respiration. The process of respiration produces carbon dioxide gas as the waste material. A part of the food taken by a living organism remains unused. The unused part of the food also becomes a waste material. Many of these waste materials are poisonous to the living things so they have to be removed.
The removal of waste substances from the body of a living organism is called excretion.
All the living things get rid of wastes from inside themselves. The important waste substances which are produced in the body of animals are carbon dioxide, urea and faeces. The animals give out carbon dioxide when they breathe out used air. The animals give out urea, unwanted water and others salts in the form of urine. The animals give out solid waste of their body in faeces.
Excretion in plants means removal of waste products in plants. The plants remove their waste products by different methods.
The main waste products produced by plants are carbon dioxide and oxygen. During the daytime, the waste product carbon dioxide is reused by plants in making food by photosynthesis. At night time, the plants get rid of waste carbon dioxide through the stomata in leaves. The waste product oxygen is also removed from plants through the stomata in leaves.
Some plants store some of their waste product in the body parts in a way that they do not harm the plant as a whole. The plant get rid of these waste by shedding of leaves, peeling of bark and felling of fruits.
Some plants remove their waste products as secretions. The plants secrete a large number of waste products like gum, resin and latex. These plant waste are useful to human beings.
The process by which living organisms produced new members of their species is called reproduction.
The modes of reproduction in different animals are different. Some animals reproduce by giving birth to their young ones whereas some animals reproduce their young ones through eggs. Human beings reproduce by giving birth to babies.
Cats, dogs, cow, horse, deer, lion and tiger etc. reproduce by giving birth to their young ones. The animals like birds and fish reproduce through eggs. Birds lay eggs which on hatching produce young ones. The birds such as hens, pigeons, parrot, duck, crow and ostrich lay eggs. When these eggs are hatched, young ones come out birds come out of these eggs.
Plants also have different modes of reproduction.
Many plants reproduce through seeds: Many plants produce seeds. When the seeds are grown in most soil, the seeds germinate and grow into new plants.
For example: Wheat, corn, paddy, Bengal gram are reproduced or grown through their seeds. Some plants through parts other than seeds. These parts can be tubers or cuttings.
Some plants reproduce through tubers : A tuber is a thickened, underground stem of a plant which is swollen with stored food.
A potato is a stem tuber. A potato stem tuber has many buds on its body. When a potato tuber is planted in the soil, then all the buds of potato tuber start growing to produce new potato plant. One old potato tuber can produce many new potato plants. It is not necessary to plant the whole potato tuber in the soil to produce new potato plants. We can even plant cut piece of potato in the soil to obtain new potato plants but each such piece should have a bud on it. A cut part of potato with a bud can grow into new potato plant.
Some plants reproduce through cutting : A small part of a plant which is removed by making a cut with a sharp knife is called a cutting. A cutting maybe a piece of stem, root or even a leaf. The cutting should be made in such a way that there are some buds on it. A cutting of existing plant having some buds on it is taken and its lower part is buried in moist soil. After few days, the cutting develops roots and grows into a new plant. The plants such as rose, henna, grapes, sugar cane and cactus.
Living things have a definite life span
All the living things start their life when they are born as babies or hatched from eggs or grow from seeds. These living things grow into adults, remain alive for a certain time and finally die. Different kinds of living things remain alive for different duration of time.
The time period for which a living things remains alive is called its life-span. All the living things have a definite life-span. Man has an average life span of 60-70 years.
The life span of some insects seen during rainy season is of only a few hours whereas the life span of a tortoise is more than 100 years.
Difference between Living and Non-living Things
|Living things||Non-living things|
|They need food, air and water.||They do not need food, air and water.|
|They grow.||They do not grow.|
|They can move on their own.||They cannot move on their own.|
|They respond to stimuli.||They do not respond to stimuli.|
|They respire||They do not respire.|
|They excrete.||They do not excrete.|
|They have a definite life span.||They do not have a definite life span.|
|Notes for Chapter 9 The Living Organisms – Characteristics and Habitats|