7.1 Adaptations, interdependence and competition

• Name and define the 4 levels of organisation within an ecosystem

  • Individual organism - a single member of a species
  • Population - a number of individuals of the same species
  • Community - multiple populations of different species living and interacting in the same area
  • Ecosystem - the interaction between the living and the non-living parts of the environment
• Define ecosystem

  An ecosystem is the interaction of a community of living organisms (biotic) with the non-living (abiotic) parts in their environment
• What 4 things do plants compete for and why?

  • Light
  • Space
  • Water
  • Mineral ions
• What 4 things do animals compete with eachother for?

  • Food
  • Territory
  • Mates
• What is interdependence?


  When each species within a community depends on other species for food, shelter, pollination etc. If one species is removed it can affect the whole community.
• What is a stable community?


  One where all the species and environmental factors are in balance so that population sizes remain fairly constant
• State the abiotic factors which can affect a community

  • Light intensity
  • Temperature
  • Moisture levels
  • Soil pH and mineral content
  • Wind intensity and direction
  • Carbon dioxide levels (for plants)
  • Oxygen levels (aquatic animals)
• How does light intensity affect community?

  Light is needed by plants for photosynthesis. More light leads to an increase in the rate of photosynthesis and an increase in plant growth rate.
• How does temperature affect community?

  Temperature affects the rate of photosynthesis in plants
• How do moisture levels affect community?

  Plants and animals require water to survive
• How does soil pH and mineral content affect community?

  Different species of plants are adapted to different soil pH levels and nutrient concentration levels
• How does wind intensity and direction affect community?

  Wind speed affects transpiration rate in plants. Transpiration affects the rate of photosynthesis as it ensures water and mineral ions are transported to leaves.
• How do carbon dioxide levels affect community?

  CO2 is required for photosynthesis in plants, so affects the rate of photosynthesis
• How do oxygen levels affect community?


  Some aquatic animals can only survive in water with high oxygen concentrations
• State the biotic factors that can affect a community

  • Availability of food
  • New predators
  • New pathogens
  • Competition
• How does the availability of food affect community?

  More food means organisms have a higher chance of surviving and reproducing. This means their populations can increase
• How do new predators affect community?

  In balanced ecosystems, predators catch enough prey to survive but no so many that they wipe out the prey population. If a new predator is introduced to the ecosystem, it may become unbalanced.
• How do new pathogens affect community?

  If a new pathogen enters an ecosystem, the populations living there will have no immunity or resistance to it so the population may decline and wipe out
• How does competition affect community?


  If two species compete for the same resources and one is better adapted to take advantage of these resources, then that species will outcompete the other. This may continue until there are too few members of the lesser adapted species to breed successfully.
• What are adaptations?


  Features that enable an organism to survive in the conditions which they live in
• Give and define the 3 types of adaptation.

  • Structural - a physical part or feature of an organism
  • Behavioural - the way an organism behaves
  • Functional - biological processes within the organism
• Give 2 examples of structural adaptation

  • The white fur of a polar bear provides camouflage in the snow so it has less chance of being detected by prey
  • Seals have a thick layer of fat (blubber) to insulate them against the cold
• Give 2 examples of behavioural adaption

  • Cold-blooded reptiles bask in the sun to absorb heat
  • Rabbits dig burrows to live in and to raise offspring
• Give 2 examples of functional adaptation

  • Snakes produce venom to kill prey
  • Mosquitos produce chemicals to stop animal blood clotting when they bite, so they can feed more easily
• What are some adaptations to cold regions?

  • Animals often have a small SA:V ratio to minimise heat loss to surroundings
  • A thick layer of fat or fur insulates against the cold and reduces heat loss
• What are some adaptations to desert regions?

  
  

  • Specially adapted kidneys which produce very concentrated urine to retain water (functional adaptation)
  • Nocturnal - only active in the early mornings, late evenings or at night when it is cooler (behavioural adaptation)
  • Some have structures to increase SA:V ratio to aid heat loss (structural adaptation)
• What are extremophiles?


  Organisms which live in very extreme environments
• Give 3 examples of extreme conditions

  • High temperature
  • High pressure
  • High salt concentration
• Give an example of where extremophile bacteria can be found

  Deep sea vents
• What are chemoautrophs?

  Bacteria which survive by using inorganic chemicals to obtain energy rather than sunlight
• What are the structural adaptations of camels?

  • Hump - store fat and metabolise into water
  • Thick coat on top of the body - insulates top of camel from heat of the sun to reduce water loss from sweating
  • Hard, leathery mouth - not damaged by spines on plants
  • Long eyelashes and can close nostrils - keep dust out of their nose
  • Wide feet - won't sink into the sand
• What are the functional adaptations of camels?

  • Little concentrated urine and dry faeces - reduce water loss / conserve water
  • Can tolerate very large changes in body temperature - less sweating so less water loss in the little water available
• What are some adaptations of plants in the desert?

  • Very small leaves - reduce water loss
  • No leaves and only spines - reduce water loss
  • Protect cactus from being eaten by animals
  • Extensive and shallow roots - catch as much water as possible after rainfall
  • Store water in stem - survive many months without rain