1.2 - Variety of Living Organisms

The features of animals and plants

• Living things are sorted into groups by the features they share, so organisms with similar features are placed together.
• The largest of these groups are called kingdoms. Two of them are the animal kingdom and the plant kingdom.

Features shared by animals and plants

• Multicellular - Both are made of many cells.
• Eukaryotic cells - Both are built from eukaryotic cells, which keep their genetic material inside a nucleus.

Features of plants

Plants are distinguished by the way they obtain their food:

• Chloroplasts - Their cells contain chloroplasts, which let them carry out photosynthesis to make their own food from simpler raw materials.
• Cellulose cell wall - Plant cells are surrounded by a cell wall made of cellulose, which gives the plant support.
• Carbohydrate storage - They store the carbohydrate they make as sucrose or as starch.

Familiar examples are the flowering plants, such as cereals like maize and herbaceous legumes like peas and beans.

Features of animals

• No chloroplasts - They cannot photosynthesise, so must take in ready-made food by eating other organisms.
• No cell wall - Their cells have no cell wall.
• Nervous coordination - Most have some form of nervous coordination, which lets them respond quickly to changes in their surroundings.
• Movement - Most can move their whole bodies from one place to another.
• Carbohydrate storage - They typically store carbohydrate as glycogen rather than as starch.

Examples include mammals, such as humans, and insects, such as houseflies and mosquitoes.