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Flashcards · Biology · Ecosystems and Communities

Levels of Organisation and Interdependence

18 cards

  1. What is an individual organism?

    One single living thing.

  2. What is a population?

    All the organisms of the same species living in the same place at the same time.

  3. What is a community?

    All the populations of the different species living in the same place.

  4. What is an ecosystem?

    A community of living organisms together with the non-living parts of their surroundings.

  5. Name the four levels of organisation, smallest first.

    Individual organism, population, community, ecosystem.

  6. A pond contains frogs, fish and plants. Is that a population or a community?

    A community, because it has several species.

  7. What does interdependence mean?

    Organisms in a community depend on each other, for example for food, shelter and pollination.

  8. Why might losing one species damage a whole community?

    Other species depend on it for food or other needs, so the effects spread.

  9. What is parasitism?

    A relationship in which the parasite benefits and the host is harmed.

  10. Name two animal parasites.

    Tapeworms and fleas.

  11. How does mistletoe harm its host tree?

    It takes water and mineral ions from the tree, weakening it.

  12. What is mutualism?

    A relationship in which both organisms benefit.

  13. What do nitrogen-fixing bacteria in root nodules gain from the plant?

    Sugars (a food supply) and a home.

  14. What does the plant gain from nitrogen-fixing bacteria?

    Nitrogen compounds that it can use to make proteins.

  15. How do cleaner fish and the larger fish both benefit?

    The cleaner gets food, and the larger fish loses its parasites.

  16. What does a flower gain from a pollinating bee, and what does the bee gain?

    The flower is pollinated, and the bee gets nectar and pollen.

  17. Four panels showing one fish, a group of the same fish, a mixed group of organisms, and a pond with sun and stones, with no labels. Name each level of organisation shown, and say what each contains. The same four panels labelled Individual, Population, Community and Ecosystem.

    Individual: one organism. Population: all the organisms of one species in the same place. Community: all the populations of the different species in the same place. Ecosystem: the community plus the non-living factors such as light, water and temperature.

  18. Three unlabelled panels showing mistletoe on a branch, root nodules on a plant, and a cleaner fish with a big fish. Name each relationship, and say which organisms benefit and which are harmed. The same three panels with headings, labels and plus and minus signs.

    Mistletoe on a tree is parasitism: the mistletoe benefits and the tree is harmed. Root nodules are mutualism: the plant gets nitrates and the bacteria get sugars. A cleaner fish and a big fish are mutualism: the big fish is cleaned and the cleaner gets food.