biology 3.1 UNIT 1

• Ecosystem


  an ecosystem consist of all the living organisms in a particular area and the non living components with which they interact
• Habitat definition

  Place where an organism lives
• Community definition

  all living organisms (plants and animals) within an ecosystem
• Population definition

  a group of organisms of the one species living in the same place at the same time
• species


  A group of organisms with similar characteristics that are able to interbreed to produce fertile offspring
• biodiversity


  biodiversity is the variety and abundance of species found in an ecosystem
• food chain


  a feeding relationship which shows the flow of energy through a series of organisms in a ecosystem
• producer


  green plant which produce its own food via photosynthesis
• consumer


  gets energy by eating something else
• micro organisms are

  decomposers, breaking their en waste material and dead animals/plants. allows nutrients to be recycled
• predator def

  animal that hunts other animals for food
• as predator numbers increase


  prey numbers decrease
• food web


  a diagram which shows how all the food chains in a community are linked together
• changes to food web

  DISESE,DROUGHT,HUNTING bc organisms interact w eachother, the removal of one population has impacts for rest
• energy in a ecosystem lost

  HEAT,MOVEMENT,UNDIGESTED MATERIALS
• how much energy passed on in food chain

  10% each time
• pyramids


  of energy and pyramid numbers
• niche


  the roll that an organism plays within a community
• interspecific competition


  individuals of a diffrent species requiring similar resources
• grazing ?
• intraspecific competition


  individuals of the same species competing for the same resources
• compare sqa terminology

  means that you should identify similarities and differences between two or more factors. You need to write something about each factor, advantages and disadvantages of each.
• define sqa terminology

  give a clear meaning or describe exactly
• Biodiversity 


  The number of different species in an ecosystem
• 5 structures in animal cell

  1. cell membrane

  2. cytoplasm

  3. ribosomes

  4. nucleus

  5. mitochondria
• 8 structures in plant cell

  1. cell membrane

  2. cytoplasm

  3. vacuole

  4. chloroplasts

  5. nucleus

  6. cell wall

  7. mitochondria

  8. ribosomes
• 5 structures in bacterial cell

  1. plasmid

  2. cell membrane

  3. cytoplasm

  4. ribosomes

  5. celll wall
• 6 structures in fugal cell

  (animal cell w cell wall)(af)

  1. cell wall

  2. cell membrane

  3. nucleus

  4. ribosomes

  5. cytoplasm

  6. mitochondria
• cell wall


  supports and strengthens cell.

  (made of cellulose, freely permeable)
• cell membrane


  controls which substances enter/ exit the cell. (selectively permeable)
• cytoplasm


  site of chemical reactions in a cell
• mitochondria


  site of aerobic respiration
• chloroplasts


  Site of photosynthesis, contain chlorophyll
• vacuole


  contains cell sap
• ribosomes


  site of protein synthesis
• plasmids


  small circular rings of DNA
• nucleus


  control cell activities, stores genetic info
• cell membrane is


  selectively permeable
• cell membrane made of 2 molecules

  1. phospholipids (skinny strings)

  2. proteins (blobs)
• what can pas through cell membrane

  oxygen, glucose, water