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 groups of organisms we are looking at:

• Plants
• Animals
• Fungi
• Bacteria
• Protoctists
• Viruses

Plants

• Are multicellular (have more than one cell) 
• Are able to photosynthesize (their cells have chloroplasts)
• Cell walls are made of cellulose
• Store carbohydrates as startch and/or sucrose

Figure 1: A typical plant cell

Examples of plants include: flowering plants (eg maize) and a herbacious legume (eg peas or beans)

Animals

• Are multicellular
• Do not photosynthesize
• Cells do not have cell walls
• Often have nervous coordination
• Are able to move from one place to another
• Store carbohydrates as glycogen

Figure 2: A typical animal cell

Examples of animals include: mammals (eg humans), insects (eg mosquitoes)

Fungi

• Cannot photosynthesize
• Body of mycelium made up of various hyphae which contain lots of nuclei.
• Some are single celled
• Cell walls made of chitin
• Feed by extracellular secretion of digestive enzymes and absorbing the organic products - Saprotrophic nutrition
• May store carbohydrates as glycogen

Figure 3: Structure of mucor, a type of fungus

Examples of fungi include: Mucor (has typical fungal hyphal structure) and yeast (single celled)

Bacteria

• Sometimes pathogenic
• Single celled
• Some can photosynthesize but mostly feed off other dead or living organisms
• Have a cell wall, cell membrane, cytoplasm, plasmids, no nucleus and have a strand of DNA instead.

Figure 4: Bacteria (note that not all have the flagellum/gelatin-like capsule)

Examples of bacteria include: Lactobacillus bulgaricus, a rod-shaped bacterium used in the production of milk and yoghurt and Pneumoccus, a spherical bacterium responsible for pneumonia

Protoctists

• Single celled
• Some resemble plant cells while others resemble animal cells
• Some are pathogenic

Figure 5: The structure of amoeba, a type of protoctist that "lives" in water

Examples of protoctists: Amoeba, which is found in pond water and Plasmodium, which is responsible for malaria.

Viruses

• Some scientists say viruses aren't living organisms while some say they are (but please don't say that in your exam!)
• Parasitic (lives off other organisms)
• Can only reproduce inside living cells
• No cellular structure, only a protein coat and one type of nucleic acid, either DNA or RNA. 

Examples of viruses: HIV virus (causes AIDS), tobacco mosiac virus (causes discoloration of leaves in tobacco plants as it stops chloroplasts from forming)