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Populations and Ecosystems Concepts

Initial perceptual naive misconceptions (any age)

Misconceptions (Explanations, Naive understanding, Misconceptions, or Perceptual responses)

Populations

  1. A change in a food web will only affect animals that prey on it.
  2. An animal that is high on the food web preys on all populations below it.
  3. A change in the prey population has no affect on the predator.
  4. If the size of one population in a food web is changed, all other populations in the web are changed in the same way.
  5. A food web is a food chain
  6. Animals are carnivores if they are big and ferocious. Herbivores are small and timid.
  7. Don't add plants to the web only prey and predator.
  8. See the top of the web as having the most energy. Or energy accumulates at the top.
  9. Populations on the top increase as the organisms below decrease.
  10. Characteristics of a population are created according to the needs of the individual or according to a predetermined grand plan.
  11. Characteristics are passed on by the bigger stronger organisms.
  12. Populations are either in equilibrium or decreasing depending on their position in the web.
  13. The needs and roles of a species are the same as those of similar species.
  14. Species live together in an ecosystem because they have compatible needs and behaviors.
  15. Plants rely on carbon dioxide from animals.
  16. Do not understand that animals energy comes from the sun.
  17. Deserts are dead waste lands where nothing could live or thrive.

Ecosystems

Beginning (preschool - 7 years)

Concepts

Populations

  1. A population consists of all individuals of a species that occur together at a given place and time

Intermediate (7 years - 11 years)

Concepts

Populations

  1. Populations of organisms can be categorized by the function they serve in a community (producer and consumer).
  2. Plants and some microorganisms are producers- they make their own food. All animals, including humans, are consumers, which obtain food by eating other organisms.

Ecosystems

  1. The population of an ecosystem depends on the resources available and abiotic factors, such as quantity of light and water, range of temperatures, and soil composition.
  2. Given adequate biotic and abiotic and no disease of predators, populations (including humans) increase at rapid rates.
  3. Lack of resources and other factors, such as predation and climate, limit the growth of a population in specific niches in the ecosystem.
  4. Relationships may be competitive or mutually beneficial.
  5. Some species have adapted to each other to the point that they could not survive without each other.

Literate (11+)

Concepts

Populations

    1. Food chains identify the relationships among producers and consumers.
    2. Food cycle includes producers, consumers, and decomposers.

Ecosystems

    1. Food webs identify the relationships among producers, consumers, and decomposers in an ecosystem.
    2. An ecosystem includes all populations living together and the physical environmental factors with which they interact.
    3. For ecosystems, the major source of energy is sunlight which is transferred by producers into chemical energy through photosynthesis.
    4. That energy then passes from organism to organism in food webs.
    5. Decomposers, primarily bacteria and fungi, are consumers that use waste materials and dead organisms for food.
    6. In the process of decomposing organic matter they create nutrients for plants.

 

Dr. Robert Sweetland's notes
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