Living and non-living things - Natural Science Junior Primary (Gr3-4)

Have a look around you.  What do you see?  Some humans, maybe an animal, the sun, the moon, the soil, plants, birds etc.  

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Now think about this - 

• which of these things are living and which are non-living
• what does it mean to be alive
• how do you know something is non-living
• an egg seems non-living, but a live chicken hatches from it, does it then mean an egg is living?
• a living thing can move.  A river moves, does that mean it is living?

Some things are very easy to see if they are living or non-living and other things are a bit more tricky.  

Many times you can have something that seems non-living but then come alive again.  Think about a seed that has been planted and takes a long time to grow - you may start thinking that it is non-living but then when the conditions are right -there is enough water and sun or after a veld fire - the seed starts growing.  We say the seed was dormant, but a seed is still a living thing.

Lets have a look at the characteristics of living things

What is a characteristic?  It is a quality belonging to something.  What is the characteristics of a door?  It is brown, a rectangular shape, made of wood etc.

The following is the qualities that a living thing has:

• It can move - plants and animals can move.  You can run and jump and a plant does not walk around but the flowers or leaves can turn itself to get more sunlight.

                                      

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• It can reproduce - humans and animals can have babies and plants make new seeds in order for new plants to grow or some plants grow from cuttings or shoots.

                                          

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• Sensing - all living things will respond to changes that happens. The leaves on a tree will turn orange in autumn, you will put on a jersey if you are cold, in winter time some animals will hibernate (go into a deep sleep for the winter)
• Breathing - all living things breathe gasses in and out.  Humans breath in oxygen and breathes out (exhales) carbon dioxide.  The plant uses the carbon dioxide again to photosynthesize (make their own food) and gives off oxygen

                                    

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• Feeding - all animals and plants need food.  Food gives all living things energy.  Green plants photosynthesizes and that is why we call them producers.

                                

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• Excreting - all living things have to get rid of waste products.  If you are hot you sweat.  You also have to visit the toilet a few times a day.  That is your body getting rid of the things it does not use and that is called waste products.  We have special organs like the skin, lungs and kidneys that can get rid of waste products.  Plants get rid of waste water through a process called transpiration.
• Growth - all living things grow.  Human babies grow into adults and seedlings grow into adult plants.

            

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The 7 qualities we have just looked at are called life processes.  For something to be living it must have ALL 7 qualities or life processes.

• See if you can name all 7 life processes that a living thing must have.

Changing from living to non-living

Something that is living can become non-living if they die.  A tree is living, but once you cut it down and you make furniture from it, the furniture is non-living.

• Look around you and see if you can make a list of things that use to be living, but are now non-living.
• Look at the list and say if it is living, non-living , was once alive, can be revived - dog, baby, traffic light, eggs, fire, trees, paper, dolphin, computer, skull, fossil and yeast (talk about this to your friend and tell them what is the reason for your answer)

To recap this information, watch the video

• You can also read the comprehension test on http://www.softschools.com/language_arts/reading_comprehension/science/21/living_and_non_living_things/
• Complete the questions on the link and also try and set your own questions on the piece and answer it.