biology b4

• Community


  Organism of different species living together in an area at a particular time
• Ecosystem


  All the living organisms and the physical environment in an area
• Population


  All the organisms of a species living in an area at a certain time
• predator


  an animal that hunts and kills other animals for food
• Adaptation


  a feature that allows an organism to live successfully in its environment
• Prey


  an animal that is hunted and killed by other animals for food
• Biotic


  The living organisms in an area and their interactions
• Abiotic


  Non-living things
• Mutualism


  A relationship between two species in which both species benefit
• Parasitism


  A relationship in which one organism gains and the other one suffers
• Predation


  An interaction in which one organism kills another for food. The population sizes affect each other
• competition


  Two or more organisms requiring the same resource
• Consumer


  And organism that gets energyvbu eating other organisms
• Producer


  An organism that can make its own organic nutrients by using sunlight
• trophic level


  The position of an organism in a food chain, Web or pyramid.
• Carnivore


  Gets its nutrients by eating other animals
• food web


  A network of connected food chains showing energy flow through a part of an ecosystem
• Herbivore


  Animal that gets energy by eating plants
• Decomposer


  Organism that gets nutrients from dead/waste matter
• food chain


  Chain showing the flow of energy from one organism to the next
• pyramid of numbers


  Diagram showing the number of organisms in each trophic level
• Types of interactions


  Competition and interdependence
• Types of interdependence

  Predation, parasitism, mutualism
• What do organisms compete for?


  CO2, mates, food shelter, water, nutrients, territory, light
• Abiotic factors examples


  Light intensity, temperature, moisture/water availability, soil pH/type, wind levels, oxygen availability
• Why is the weight of biomass measured rather than number of organisms for a pyramid of numbers?


  Because it helps show you how much food is needed to sustain an organism
• Biomass


  the mass of living matter
• How do you calculate biomass from a pyramid of numbers?


  Number x mass per individual in a species
• types of ecosystems


  terrestrial and aquatic
• How is energy lost in a food chain?


  -only 2 to 5% of sunlight hitting the leaf is absorbed

  
  

  -respiration, affected by: maintaining temperature, movement, metabolism

  
  

  -waste:faeces (undigested food) and urine (protein is wasted)

  
  

  -heat loss

  
  

  -inedible parts of organisms mean the whole thing isn't eaten.
• Pyramid of energy


  Laid out like a pyramid of numbers but is based on the amount of energy in each trophic level rather than the number of organisms.
• How to calculate efficiency of biomass


  Efficiency =(biomass after transfer / biomass before transfer) x 100
• What's the efficiency is 90g of nemo and dory eat 15000g of algae?


  90/15000 x 100 = 0.6%
• Sampling


  Taking observations from a smaller area to represent a larger area
• Why might à sample not be accurate?


  -it's only an estimation

  -the sample size should have been big enough to be representative
• abundance


  How big a species' population is in an area
• Distribution


  Where organisms are found in the habitat
• What are the 2 ways you can use a quadrat?


  Count the number of organisms or use percentage cover by splitting it into a 10 x 10 grid
• Why do all the percentages add up to over 100% in the percentage cover method


  Because many species will live on / in other species.
• If there are organisms that fall partially outside the quadrat, what do you do?


  You can count it if you want, but you must be consistant throughout.