Kategorier: Alla - viruses - bacteria - fungi - plants

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Biology topic 1

Viruses are unique entities that do not carry out life processes independently, only reproducing within a living host. Examples include Influenza, HIV, and Ebola. They lack cellular structures like cell membranes and are significantly smaller than bacteria, classified as non-living pathogenic agents.

Biology topic 1

Biology topic 1

Protoctists

Animal like
E.g. Plasmodium (causes malaria)
Plant-like protoctists
E.g. Chlorella
Usually aquatic
This is a dump group

Funky Fungi

Have chitin cell walls
Fungi form hyphae (finger like structures)
Store carbohydrates as glycogen
no chloroplasts so carry out saprotrophic nutrition
Secretes extracellular enzymes which break down large , insoluble molecules into small, soluble molecules which the fungi then absorbs.
Single celled: yeast
Multicellular: Mucor or mould

Plants

e.g.
Herbaceous legumes: peas

NB legumes means to fix nitrogen out of the atmosphere

cereals: maize
Store carbohydrates as starch and sucrose
Contains chloroplasts THEREFORE can photosynthesise
Cellulose cell wall

Viruses

PATHOGENIC IN ALL ORGANISMS
E.g. Influenza, HIV,Ebola etc.
No cell membrane, just a protein coat
No cellular structure
Much smaller than bacteria
Do not carry out life processes Except reproduction BUT only when in a living host organism
NOT living organisms
DO NOT Carry out life processes

To be classified as a living organism, you must carry out the seven life processes: M- ovement R - espiration -> release of energy from food S - ensitivity -> topic 11 G - rowth -> topic 13 R - eproduction -> topic 12 E - xcretion -> topic 10 N - utrition ->topic 5 + 6

Bacteria

DNA in nucleoid
E.G. Spherical-shaped --> Streptococcus
E.G. rod-shaped --> Lactobacillus bulgaricus
All have a cell wall
some feed on other organisms
If they are dead, bacteria is a decomposer
If living, bacteria is a parasite
Some have chloroplasts
Single-Celled

Animals

E.G.
Insects: housefly or mosquito
Mammals: humans
Nervous communication so can move from place to place
store carbohydrates as glycogen
No chloroplasts THEREFORE can't photosynthesisze
No cell wall
Multicellular