Section 1 b) Summary

Living organisms are organised into categories based on shared characteristics. The seven taxonomic groups of classification are:

• Kingdom (e.g. Animalia)
• Phylum (e.g. Chordata)
• Class (e.g. Mammalia)
• Order (e.g. Carnivora)
• Family (e.g. Canidae)
• Genus (e.g. Canis)
• Species (e.g. Lupus)

Species are internationally known by their binomial classification, which is a two-part latin name composed of species and genus used to identify groups of organisms that share similar characteristics and are able to breed to produce fertile offspring. In the above example, the species would be known as Canis Lupus (Grey Wolf). 

All living organisms fall under the five kingdoms of classification: Animals, plants, bacteria, fungi and protoctists. Each of these groups is defined by their own set of characteristics:

Animals
Multi-cellular, No cell walls, No chloroplasts = No photosynthesis, therefore they must consume other organisms to gain energy. Cells move freely.

Can move their entire body due to nervous system.
Glycogen - how animals store carbohydrates
Vertebrates are animals with spines/backbones
Invertebrates are animals without spines/backbones

Vertebrates can be split into the following categories:

• Mammals (warm-blooded, secrete milk, give birth to live young, have lungs, most have hair)
• Birds (warm-blooded, feathers, wings, beaks, hard shelled eggs, have lungs)
• Fish (cold-blooded, jelly-coated eggs laid in water, scales, fins and gills)
• Reptiles (cold-blooded, leathery-shelled eggs, scales, have lungs)
• Amphibians (cold-blooded, jelly-coated eggs laid in water, moist skin, gills when young, lungs when mature)

E.g. Cat, Dolphin, Owl, Chicken, Cod, Haddock, Adder, Blue-tongue Lizard, Salamander, Frog

Plants
Multi-cellular, Cellulose cell walls, Chloroplasts for photosynthesis, absorb water through their roots and up the xylem vessel by osmosis.

Move leaves etc. to face the sun
Starch or Sucrose - how plants store carbohydrates
Carnivorous plants: some plants adapt to nutrient-poor soil by attracting, trapping and digesting insects or small animals to gain nutrients from them.

E.g. Sunflower, Cacti, Oak, Yew, Palm

Bacteria
Uni-cellular, No Nucleus (Plasmid and DNA loop instead), Polysaccharide or Protein cell wall, some have Chloroplasts, all have Mesosomes

Some have flagellum for free movement
Glycogen or Lipid food stores

E.g. Lactobacillus Bulgaricus, Pneumococcus, Escherichia Coli (E.Coli), Salmonella

Fungi
Multi- or uni-cellular, Chitin cell walls, organised in fungal hyphal structures with threads/fibres called hyphae, which organise into mycelium.

Fungi feed through saprotrophic nutrition, also known as extracellular digestion. The cells secrete digestive enzymes to break down organic matter, which is then absorbed by the fungus.
Glycogen- how carbohydrates are stored in fungi

E.g. Yeast (uni-cellular), Mucor (multi-cellular)

Protoctists
Uni-cellular, characteristics vary: some resemble animal cells, some resemble plant cells, some are pathogenic

E.g. Amoeba, Plasmodium, Chlorella

Viruses are not classified as living organisms, they are a special case; they don't perform all seven life functions, and they can only reproduce inside a living cell. They are parasitic and pathogenic.

E.g. Human Immunodeficiency Virus (H.I.V), Influenza, Tobacco Mosaic Virus



Pathogens
A pathogen is a disease-causing particle or organism. It infects a living organism and inhibits their normal function. Pathogens can be viruses, bacteria, protoctists or fungi.