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2013-04-28 08:50:49
biology ecology

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  1. Environment
    All the external factors that influence an organism
  2. What is ecology?
    Ecology is the study of how living things relate to each other and to their environment
  3. What is an ecosystem?
    An ecosystem is a group of clearly distinguished organisms that interact with each other and their environment as a unit
  4. Community
    A community is all of the organisms in an ecosystem
  5. Population
    A population is all the members of the same species in an ecosystem
  6. What is a biosphere?
    The biosphere is the part of the planet containing living organimss
  7. What is a habitat?
    A habitat is the particular place within the ecosystem where an organism lives
  8. Environmental factors that affect organisms
    • Abiotic - non living factors
    • Biotic - living factors
    • Climatic - weather conditions over a long period of time
    • Edaphic - factors referring to the soil
  9. Abiotic factors
    • Temperature of land and water
    • pH
    • Light intensity
    • Water
  10. Biotic factors:
    • Plats - food and shelter
    • Predators - reduce number of prey
    • Prey
    • Parasites
    • Humans (pollution)
  11. Climatic factors:
    • Temperature
    • Rainfall
    • Wind
  12. Edaphic
    • Soil pH
    • Available water
    • Air and mineral content
  13. Aquatic factors
    • Light penetration
    • Currents
    • Wave action
  14. What are producers
    Producers are organisms that carry out photosynthesis
  15. What are primary consumers
    Primary consumers feed on producers
  16. What are secondary consumers
    Secondary consumers feed on primary consumers
  17. What is the food chain
    A sequence of organisms in which each one is eaten by the next member in the chain
  18. A grazing food chain is..
    One where the initial plant is living
  19. A detritus food chain is..
    One where the chain begins with dead organic matter and animal waste (detritus)
  20. What is a food web
    2 or more interconnected food chains
  21. What is tropic level
    Refers to position of an organism in a food chain
  22. Limitations of pyramid of numbers
    Size (e.g. Single rosé bush can support thousands of green flies) INVERTED

    distorted when parasites
  23. What is a niche
    A niche is the functional role of an organism in an ecosystem
  24. Carbon dioxide is returned to the environment by
    • 1. Respiration in plants, animals and microorganisms
    • 2. Decay caused by microorganisms
    • 3. Combustion ie. fossil fuels
  25. Nitrogen gas must first be..
    Nitrogen gas must first be 'fixed' ie changed to a suitable form (ammonia in nitrate)
  26. Why do organisms need nitrogen?
    Protein, DNA and RNA manufacture
  27. Nitrogen fixation is
    A conversion of gaseous nitrogen to a form that can be used by organisms
  28. Nitrification is
    The conversion of ammonia to nitrites and then to nitrates
  29. Denitrification is
    The conversion of nitrates into nitrogen gas
  30. What is pollution
    Pollution is any undesirable change to the environment
  31. What is eutrophication
    A condition where lakes become over enriched with nutrients, resulting from excess artificial fertilisers washed into rivers and lakes
  32. How to control slurry pollutant
    Avoid spreading on wet, frozen, sloping land
  33. Cause of acid rain
    Fossil fuels release acidic CO2 and SO2
  34. Problems with acid rain
    • Erosion of limestone
    • Lower soil pH
    • Breathing problems
  35. Solutions of acid rain
    • Burn less fossil fuels
    • Switch to clean energy
  36. What is conservation
    Conservation is the protection and wise management of natural resources and the environment
  37. Benefits of conservation
    • Existing environments are maintained
    • Endangered species are preserved for reproduction
    • The balance of nature is maintained
    • Pollution and it's effects are teduced
  38. Problems with waste disposal
    • Availability of suitable landfill sites
    • Toxic or polluting content of fumes from incineration
    • Decaying waste produces methane
    • Harmful substances may leak into ground water supplies
  39. Solutions for waste disposal
    Use microorganisms

    Reduce reuse recycle
  40. Accumulated fish waste leads to
    • Unpleasant odours
    • Infestation of rats
    • Maggots
  41. Managing fishery waste
    • Animal feeds and oils
    • Fish offal is converted to fish meal and this is sold as animal Feed
    • Oil is extracted, refined, health food supplements
  42. Factors that control population
    • 1. Completion
    • 2. Predation
    • 3. Parasitism
    • 4. Symbiosis
  43. Animals live in populations because
    • Food and shelter
    • Safer in a group
    • Availability of a mate for breeding purposes
  44. What is competition
    When organisms of the same or different species "fight" for the necessary resources that are in short supply
  45. Intra specific competition
    Between members of the same speoes
  46. Inter specific competition
    Between members of different species
  47. Plants compete for..
    Light, water, minerals and space
  48. Animals compete for..
    Food, water, shelter, territory and mates
  49. Contest competition
    Involves an active physical confrontation between two organisms
  50. Scramble competition
    Is when each organism tries to acquire as much of the resource as poddible
  51. Competition and population size..
    • Restricts population size
    • Only successful competitors survive and reproduce
    • A driving force behind ecolutoon
  52. How do animals survive competition?
    • Changing feeding habits
    • Camouflage
    • Producing protective costs
    • Moving away from over populated areas

    • Plants
    • Produce large number of seeds
    • Plants thrive even in poorer soil conditions
  53. What is predation
    The act of some animals capturing and killing other animals for food
  54. Predators are
    Animals that hunt, kill and eat other animals for food
  55. Positive effects of predation
    • Stabilises the community
    • Control the number of herbivores, prevent overgrazing
    • Eliminate the less well adapted prey
  56. Adaptions of predators
    • Keen senses and sharp teeth
    • Catch easiest prey, old and sick
    • Live and hunt in packs
    • Migrate to where prey is plentiful
    • Camouflage
  57. Examples of adaptions of predators
    • Hawks have good eyesight
    • Cheetahs can run at 60km/hr
  58. Adaptations of prey
    • Plants have thorns, spines or stings
    • Nasty taste when eaten
    • Are faster than their predators
    • Safety in numbers
    • Camouflage
  59. What is parasitism
    One organism, the parasite, benefits from another, the host, and does harm to it
  60. Symbiosis
    Where two organisms of different species have a close relationship where at least one of them benefits
  61. Factors that contribute to predator prey relationships
    1. The availablity an abundance of food

    • 2. Concealment
    • Less prey, hide better. Allows population to survive and increase

    • 3.Movement of prey and predators
    • When not enough food, prey will migrate
    • Predator moves to area with more pret
  62. Population increase because
    • Immigration to new area
    • Rise in birth rates
  63. Population decrease because
    • Death
    • Emigration
  64. 4 factors that affect human population
    • 1. Famine
    • 2. War
    • 3. Disease
    • 4. Contraception