BIOLOGY SENIOR ONE THE FIVE KINGDOMS

The Five Kingdoms of Living Organisms

Kingdom Monera

This    kingdom          includes           the       simplest           and smallest living organisms. The organisms are single-celled known as bacteria.

The bacteria have the following characteristics:

• They are       unicellular       (single celled) organisms
• The bacteria are grouped according to their shapes which can be rounded, coiled or rod-shaped.
• They have no true nucleus. Their genetic material is not enclosed by the nuclear membrane.

 Useful and Harmful aspects of Monera

Some people may tend to fear bacteria, because they only imagine that bacteria cause harm. However biological studies show that bacteria can be both harmful and useful in nature.

Bacteria are harmful because:

1. They cause diseases e.g. tuberculosis and cholera in humans.
2. Action of bacteria on food makes it rot.

Bacteria are useful because:

1. They help in the process of decomposition by breaking up organic wastes.
2. They contribute to soil fertility by fixing nitrogen which is important for plant growth.
3. Some bacteria are used in treatment of sewage.
4. Some bacteria are used in industry e.g. in making of food like yoghurt.

 Kingdom Protoctista

This kingdom consists of single celled and simple multicellular organisms that possess a true nucleus unlike monera.

Examples are:

1. Amoeba: does not have a permanent shape. It moves by use of pseudopodia (pseudo- means false while podia – is to do with limb). It causes dysentery in man.
2. Paramecium: is oval shaped. It moves by use of hair-like structures called cilia. It feeds on other microorganisms e.g.

bacteria.

3. Plasmodium causes malaria in humans.

Kingdom Fungi

Kingdom fungi include mushrooms, yeast and moulds. Some fungi grow in wood and soil, and develop from tiny spores. Fungi have a nucleus and their cells have a cell wall made up of a substance known as chitin. They do not make their own food; instead feed on the decomposing organic matter of animals and plants.

You may already be aware that some types of fungi like mushrooms are grown and eaten while others like puff balls are poisonous. This informs you that fungi can be useful or harmful in nature.

Useful Aspects of Fungi

1. Fungi keep soil fertile by recycling organic material through decomposition.
2. Some fungi are food for humans, for example, mushrooms.
3. Manufacture of medicine, for example, antibiotic Penicillin

Yeast is a type of fungus used in baking of bread and brewing of beer in industries.

Harmful Aspects of Fungi

1. They cause diseases e.g. ringworm, candida, athletes’ foot (in animals), potato blight and leaf rust in coffee.
2. Fungi like moulds when they grow on food they cause food spoilage.