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A Comprehensive Guide to Homeschooling

What happens when living things die?


What do rot (decay away) and die on Earth?

Living things. These include all plant and animal matter.

 E.g. – A log was once the trunk of a tree. Now it is dead and decaying.


Why the Earth is not covered with the bodies of dead animals and plants?


The nature has a way of disposing (transferring to another) of dead things. There are some tiny living things that feed on dead animals and plants bodies. Therefore the dead animals and plants bodies gradually rot or decay away. So the Earth is not covered with the bodies of dead animals and plants.

What is the other name given for rotting or decaying?


E.g.- Decaying vegetables is a very good example for decomposing


What are ‘decomposers’?

The organisms that feed on dead plants and animals are called decomposers.


What are the examples for decomposers?


1) Bacteria

2) Fungi (singular- Fungus)

3) Algae

4) Lichen (Lichens grow on large trees absorbing all the nutrients of the large trees and gradually the lichen is growing, but the large tree is dying.)


How do decomposers decompose dead plants and animals?


First the decomposers such as bacteria and fungi produce a liquid that slowly dissolves the dead plant or animal they are feeding on. Then they absorb this liquid back into themselves. It can take a long time for a large plant or animal to be decomposed away than dead leaves.


The 3 main factors that affect the rate of decay are;


  • moisture
  • temperature
  • amount of available oxygen


What are helpful to decomposers for decomposing?


1) Invertebrate animals (animals without a backbone) such as Woodlice, millipedes, earthworms.

2) These invertebrate animals break up the dead leaves on the floor of a wood into small pieces.


Why is decomposing very important in our environment?


1) Earth won’t be covered with the bodies of dead animals and plants.


2) Decomposers return the energy and nutrients of the dead bodies to the environment.



Decaying away


Examples for decaying away


1) Stale bread and fruits go brown or mouldy (Covered with or smelling of mould) when it starts to decay.


2) Many deciduous trees lose their leaves in winter. The piles of dead leaves on the ground soon begin to decay away.


decaying leaves


E.g. – 1) You can see the skeletons of leaves of a tree left on the ground.

       2) Fallen logs feel soft and crumbly where they are decaying away. 





What are micro-organisms?

Micro-organisms are very tiny living things that can be seen only with a microscope.


What is the other name given to micro-organisms?



What are the examples for micro-organisms or microbes?


1) Bacteria

2) Fungi

3) Viruses


What are ‘germs’?

Micro-organisms that cause diseases and make us ill are often called germs.


Where can micro-organisms live?

Micro-organisms can live all around us, in the air, in our bodies and in water.


Are all micro-organisms harmful?

Some micro-organisms are harmful to us, but others are helpful to us.


What are the fungi that can be seen without a microscope?


1) Mushrooms

2) Toadstools

3) The moulds that grow on stale bread and rotting fruits (we can notice them only if lots of them are growing together)


Mushrooms – Some mushrooms can be eaten. There are many colourful kinds of fungi which are poisonous, although they do help materials to decay away, but they cannot be eaten.


Moulds – Moulds are small fungi, which cause bread and other organic materials to decay away.





What is compost?

Compost is a mixture of decomposing matter used to improve the quality of soil and make soil fertile.


How can we make use of the bacteria and fungi that decompose waste material?

By making a compost heap


a compost heap



What are the best materials to make compost?


Soft matter such as:

1) Grass mowing

2) Dead leaves

3) Tea leaves

4) Straw (hay)

5) Vegetable and fruit peelings

How is compost made?


The waste material pile is built by layering different kinds of waste in a bin. There are spaces between the layers for air to circulate (move around the bin). The waste material pile needs heat for rotting and killing all unwanted organisms. The material decays faster if the, heap is turned and mixed up every few weeks. After a month or two the compost heap becomes a pile of crumbly, dark material called compost. The compost is then applied to plants as a fertilizer.


What is ‘humus’?

The decayed plant and animal material in the soil.




How is humus formed?

If compost is dug into the soil, it will form humus.


How is humus important?


1) It improves the soil texture.

2) It slowly decomposes away to form mineral salts that plants can use as food.