Section 1 b) Specification

1.2 describe the common features shared by organisms within the following main
groups: plants, animals, fungi, bacteria, protoctists and viruses, and for each
group describe examples and their features

The five kingdoms of classification are plants, animals, fungi, bacteria and protoctists. Viruses are not classified as living organisms, but they are a special case (they can carry out all of the functions of living organisms within a living cell)

Animals (Animalia) are multi-cellular organisms that need to feed off other living organisms as they do not contain chloroplasts for photosynthesis. Animal cells have no cell walls and are able to move freely. Animals are able to move their entire body due to their nervous system. They store carbohydrates as glycogen in their muscles.
Examples include: Humans, Fish, Bumble Bees, Chicken, Tortoises, etc.

Plants (Plantae) are multi-cellular organisms that contain chloroplasts to produce food through photosynthesis. They have cellulose cell walls, that provide the plant with structure and support, and they store carbohydrates as starch or sucrose. Carnivorous plants such as the venus flytrap are able to catch and digest small animals in order to obtain nutrients in poor soil.
Examples include: Rice, Sunflowers, Bananas, Beans, Roses, Wheat, etc.

Protoctists (Protoctista), also known as the 'dustbin kingdom', are a kingdom of greatly varied uni-cellular organisms. Some have characteristics of animal cells, some photosynthesize like plant cells, and some are pathogenic.
Examples include: Chlorella, Amoeba, Plasmodium, Euglena, Paramecium, etc.

Fungi (Fungus) can be multi- or uni-cellular. They cannot photosynthesize, so they must feed off other organisms. They do this through saprotrophic nutrition, the secretion of digestive enzymes into the surrounding environment to break down nutrients the fungus will then absorb the broken-down organic matter (this is also known as extracellular digestion, it happens outside the cell). Their bodies are organised in a fungal hyphal structure: they look like threads called 'hyphae', which are organised in mycelium. They have chitin cell walls and store carbohydrates as glycogen.
Examples include: Yeast (uni-cellular), Mucor, Basidiomycota, etc.

Bacteria (Prokaryotes) are uni-cellular organisms without a nucleus, instead containing a loop of DNA and a plasmid, which can move between cells. They have polysaccharide or protein cell walls, glycogen or lipid food stores and mesosomes for respiration. Some have flagellum to allow them to move, or chlorophyll to carry out photosynthesis (however most feed off other living organisms)
Examples include: Pneumococcus, Lactobacillus bulgaricus (used to make yoghurt), E.Coli, etc.

Viruses are much smaller than bacteria, and all are parasitic. They can only reproduce inside living cells, and don't carry out all of the seven life processes. Viruses are made up of genetic material and a protein coat. All viruses are pathogenic, disease-causing.
Examples include: Influenza, Human Immunodeficiency Virus (HIV), Tobacco Mosaic Virus, etc.

1.3 recall the term ‘pathogen’ and know that pathogens may be fungi, bacteria,
protoctists or viruses.

A pathogen is a disease-causing micro-organism. Pathogens include bacteria, viruses, fungi and protoctists.
Examples of pathogens:

• E.Coli (Bacterium)
• Influenza (Virus)
• Candida (Fungus)
• Pneumococcus (Bacterium)
• HIV (Virus)
• Cryptococcus (Fungus that causes meningitis)