The nature and variety of living organisms

Characteristics of living organisms include;

Movement

Respitation

Sensitivity

Growth

Reproduction

Excretion

Nutrition

Control

Plant: (maize or beans)

• Multicellular organisms
• Cells contain chloroplasts and are able to carry out photosynthesis
• Cells have cellulose cell walls
• They store carbohydrates as starch or sucrose.

Animals: (humans and houseflys)

• Multicellular organisms
• Cells do not contain chloroplasts and are not able to carry out photosynthesis
• Cells have no cell walls
• They have a nervous system
• They often store carbohydrate as glycogen

Fungi: (Mucor and Yeast)

• They are saprophytic and feed by excreting digestive enzymes onto food and absorbing the digested products
• Cells do not contain chloroplasts and are not able to carryout photosynthesis
• Cells are joined together to form threads, called hyphae.
• Hyphae contain many nuclei, because they are made from many cells.
• Cell walls are made from chitin (a protein)
• They store carbohydrates as glycogen.

Bacteria:(Lactobacillius bulgaricus)

• Made from single cells
• Cells do not contain a nucleus, but have a small piece of circular DNA instead (a bacterial chromosome).
• Some bacteria can carry out rudimentary photosynthesis, but most are saprophytes

Viruses: (Mucor and Yeast)

• Much smaller than bacteria. They are not made from cells
• Totally parasitic and reproduce inside host cells.
• They infect every type of living cell
• They have the structure below (learn it, it comes up!)