Showing posts with label living organisms. Show all posts
Showing posts with label living organisms. Show all posts

Tuesday, 2 December 2014

2a) Levels of Organisation

Some organelles (tiny structures within cells) found in a typical  animal cell:

  • nucleus 
  • cell membrane 
  • cytoplasm 
Found in plant cell:
  • Chloroplasts 
  • Cell wall 
  • Vacuole 
And some cells are specialised 

Section 2

Structures and functions in living organisms

Wednesday, 26 November 2014

1b) Variety of living organisms



Organisms
Description
Examples
Plants
Multicellular
Chloroplasts: photosynthesise
Cell walls: out of cellulose
Store carbohydrates: starch
Trees
Cereals
Legumes
Animals
Multicellular
No cell walls
Store carbohydrates as glycogen
Fat cells
Cells can change shape
Mammals
Insects
Fungi
Single-celled
Mycelium: hyphae which has leads of nuclei
Cell walls made of chitin
Starch stored
Mushrooms
Puffballs
Yeasts
Mucor
Bacteria
Single-celled and microscopic
No nucleus
Circular chromosome of DNA
Some can photosynthesise
Feed off other organisms
Salmonella
Typhi
Vibrio
Protoctists
Single-celled and microscopic
Chlorophasts and similar to plant cells some animals cells
Chlorella
Amoeba
Viruses
Not living
No cells
Don' t store energy
Hide in living cells
Can't detect them (antibodies)
HIV
AIDS


1a) Characteristics of living organisms


Movement
Respiration - getting energy from food
Sensitivity - detecting changes in surroundings
Growth - grow and develop into adult form
Reproduction - make new generations of a species
Excretion - getting rid of waste products
Nutrition - taking in and using food as a supply of energy