Respiration, Excretion and Reproduction

The Living Being and Their Surroundings of Class 6

Respiration

Respiration is the chemical process in which food is taken by an organism combines with oxygen to release energy. All the living things (plants and animals) undergo respiration to obtain energy from food. The process of taking air into the lungs through nose and then expel it through nose is called breathing. The purpose of breathing in air is to provide oxygen to our body for carrying out respiration. Thus, breathing is a part of the process of respiration. 

Some animals do not have lungs like human beings for breathing or exchange of gases, so they have different mechanisms for breathing (or exchange of gases). 

respiration

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 (of air) needed for respiration through its thin and moist skin 

earthworm

The fish has special organs of breathing called gills. The gills absorb oxygen dissolved in water. 

fish

 Like animals, plants also need energy. The plants get this energy by the process of respiration. The plants use oxygen (of air) for respiration and release carbon dioxide in this process. Every leaf of a plant has a large number of tiny pores (or holes) called stomata on its surface. The oxygen (of air) enters the plant leaves through stomata and utilized in respiration. The carbon dioxide produced during respiration inside the plant is also expelled from the leaves through stomata. Thus, the exchange of gases (oxygen and carbon dioxide) in plants during respiration takes place through the tiny pores in their leaves called "stomata". Thus, respiration is essential for all living organisms

Excretion

The removal of waste substances from the body of a living organism is called excretion. All the living things excrete. That is, all the living things get rid of wastes from inside themselves (which they do not want).

The animals give out carbon dioxide when they breathe out used air. The animals give out urea, unwanted water and other salts in the form of urine. The animals give out solid wastes of their body in faeces. Some harmful or poisonous waste materials are also produced in plants. So, plants also excrete.

excretion

Some plants store some of their waste products in the body parts (like leaves, bark and fruits) in a way that they do not harm the plant as a whole. The plants get rid of these wastes by the shedding of leaves, peeling of bark and felling of fruits.

Thus, Excretion is another characteristic common to all living things.

Reproduction

The process by which living organisms produce new members of their species is called reproduction. All the living things reproduce themselves. The modes (or methods) 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. For example, human beings to babies. The animals like birds and fish reproduce through eggs.  Plants also reproduce (to give new plants).

reproduction

Many plants reproduce through seeds. When the seeds are sown in the moist soil, the seeds germinate and grow into new plants.

Some plants reproduce through tubers.  A tuber is a thickened, underground stem (or root) of plant which is swollen with stored food.

Thus, reproduction is essential for the survival of a species on this earth.

Living Things have a Definite Life-Span

All the living things have a definite life-span. For example, man has an average life-span of 60 to 70 years. This means that the average duration of life of man on this earth is 60 to 70 years. Different living things have different life-spans. For example, 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.

Differences between Living Things and Non-Living Things

differences

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