Chapter 2- The Variety of Living Organisms
- Created by: Zainaaax
- Created on: 25-06-15 20:40
View mindmap
- Chapter 2- The Variety of Living Organisms
- Plants
- Multicellular
- Bodies made up of many cells
- Contain chloroplasts=photosynthesis
- Process using light energy to convert simple inorganic molecules e.g water + co2 into complex organic compounds
- Make starch through photo' and sucrose= sugar
- Multicellular
- Animals
- Multicellular
- No chloroplasts in cells= no photo'
- Gain nutrition by feeding on other animals/ plants
- No cell walls
- Therefore cell can change shape
- Movement controlled by coordination of nervous system
- Store carbohydrate in cells as glycogen
- Fungi
- e.g mushrooms and toadstools
- Multicellular
- Yeast= unicellular
- No chloroplasts=no photo'
- Cell walls= made of chitin
- Cells joined together to form threads= hyphae
- Saprophytic-> feed by excreting digestive enzymes onto food and absorbing digestive products
- e.g mushrooms and toadstools
- Protoctists
- Mixed group of organisms
- Don't fit into group of plants, animals or fungi
- Microscopic and single-celled organisms
- Some resemble animal cells e.g amoeba
- PROTOZOA
- Some resemble plants
- ALGAE
- Unicellular but e.g. seaweed= multicellular
- ALGAE
- Some have chloroplasts=photo'
- Some= agents of disease e.g plasmodium-> malaria
- Mixed group of organisms
- Bacteria
- Single-celled organisms
- smaller < plant/animal/prot cells
- Simple structure
- e.g animal cell=10-15 um in diameter
- Bacteria cell= 1-5 um in length
- All have cell wall- protects and supports shape of cell
- Polysaccharides and proteins
- Some species have layer outside wall= capsule/slimelayer
- Gives bacteria cell extra protection
- Some species have layer outside wall= capsule/slimelayer
- Polysaccharides and proteins
- Underneath cell wall= cell membrane
- Cytoplasm= centre of cell
- No nucleus, therefore genetic mat'l in single chromosome within cytoplasm forming circular loop
- Plasmids in cytop'
- small circular rings of DNA carrying bacterium's genes
- DON'T EXIST IN ALL BACTERIUM CELL
- Some have chlophyll to c/o photo'
- DON'T EXIST IN ALL BACTERIUM CELL
- small circular rings of DNA carrying bacterium's genes
- Cytoplasm= centre of cell
- Some bacteria can swim- propelled by flagella
- Others do not
- Most feed off dead organisms
- Like fungi bacteria can recycle dead organisms and waste products in soil and elsewhere
- Some used to make food like yoghurt and milk
- Other bacteria= pathogens i.e cause disease
- living organisms c/o life processes
- Viruses
- All viruses=parasites-> repro inside living cells
- Need host cell to live in- plant/animal/bacterial cells
- Viruses smaller < bacteria
- Need host cell to live in- plant/animal/bacterial cells
- Viruses not made of cells
- No nucleus, cytoplasm, composed of core genetic mat'l surrounded by protein coat
- Genetic mat'l= DNA, RNA
- No nucleus, cytoplasm, composed of core genetic mat'l surrounded by protein coat
- Membrane= envelope surrounds virus particle, stolen form surface membrane of host cell
- Viruses= no MRS GREN except reproduction
- Border on being living/non-living organism
- Reprods by taking over host cells' machinery to make virus particles. After more made-> host cell dies and particles released to infect more cells
- Viruses e.g influenza made like this
- However, body's immune system destroys person therefore person recovers
- Sometimes immune system doesn't destroy virus quickly enough-> causes permanent damage or death. Virus may attack cells (HIV w/c causes AIDS)
- However, body's immune system destroys person therefore person recovers
- Viruses e.g influenza made like this
- Some infect plant cells too
- All viruses=parasites-> repro inside living cells
- Plants
Comments
No comments have yet been made