Classification and Organisation (1.1-1.4)

characteristics of living organisms

movement, respiration, sensitivity, homeo stasis, growth, reproduction, excretion and nutrition

key features of plants

• they are multicellular

• cells contain chloroplasts

• they carry out photosynthesis

• cell walls made of cellulose

• store carbohydrates as starch/sucrose

key features of fungi

• cell walls made of chitin

• saprotrophic nutrition

• reproduce by producing spores

• body organised into a mycelium made from hyphae

key features of animals

• multicellular

• no cell walls

• usually have nervous coordination

• store carbohydrates as glycogen

• heterotrophic nutrition

key features of protoctista

• microscopic

• single-celled

• reproduce sexually or asexually

key features of bacteria

• prokaryotic

• unicellular

• contain a circular chromosome of DNA

• come in spheres, rods and spirals

cellular organisation

organelle - cell - tissue - organ - system - organism

what is a pathogen?

a microorganism that can cause disease or harm

can be: viruses, fungi, bacteria or protoctista

key features of viruses

• non-living

• parasitic - can only reproduce inside host cell

• infect every type of living organism

• no cellular structure but has a protein coat

• contain one type of nucleic acid: either DNA or RNA

function of nucleus

contains genetic information and controls cell activity

function of cell membrane

a selectively permeable barrier that controls the entry and exit of substances

function of mitochondria

produces ATP through cellular respiration, providing energy for the cell

function of ribosomes

site of protein synthesisers

function of cytoplasm

site of chemical reactions in the cell

function of cell wall

structural support

function of a permanent vacuole

stores cell sap (sugar + water)