(5-8) B2

Science Curriculum Preview Committee Clarification of Learning Results

Revised 04/08/04

5-8

B2: Analyze how the finite resources in an ecosystem limit the types and populations of organisms within it.

Curriculum Organizing Questions

What types of resources limit the population of this organism?

What are some of the populations of organisms in this habitat?

What does this population depend on in order to meet its basic needs?

What other organisms depend on this organism in order to be able to meet their basic needs?

What are some examples of environments that have become overpopulated?

Elaboration
The amount of life any environment can sustain is limited by its most basic resources: the inflow of energy, minerals, and water. Organisms compete with one another for finite resources. As any population of organisms grows, it is held in check by one or more environmental factors, such as lack of resources, increased predation, or lack of nesting sites. Organisms can only survive in environments where their basic needs are met. NSES C4a

Specific Ideas

In all environments- freshwater, marine, forest, desert, grassland, mountains, and others- organisms with similar needs may compete with one another for resources, including food, space, water, air, and shelter. Benchmarks 5D1

Some resources are renewable, and some are finite. Renewable resources are ones that are replenished by cycles in the ecosystem as fast as (or faster than) they are removed.

A population consists of all individuals of a species that occur together at a given place and time. All populations living together and the physical factors with which they interact compose an ecosystems. NSES C4a

Lack of resources and other factors, such as predation and climate, limit the growth of populations in specific niches in the ecosystem. NSES C4d

The output from one part of a system can become the input for another part of it. Benchmarks 11A2

When an area becomes overpopulated, the environment can become degraded due to the increased use of resources.

Developmental & Instructional Implications

Students may believe that organisms are able to effect changes in bodily structure to exploit particular habitats, or that they respond to a changed environment by seeking a more favorable environment. Teachers should challenge the misconception that the ocean is a limitless resource and that humans are indestructible as a species.

Examples

Back to Big Ideas Grid B Back to Standard B Back to Index

Curriculum Organizing Questions	What types of resources limit the population of this organism? What are some of the populations of organisms in this habitat? What does this population depend on in order to meet its basic needs? What other organisms depend on this organism in order to be able to meet their basic needs? What are some examples of environments that have become overpopulated?
Elaboration	The amount of life any environment can sustain is limited by its most basic resources: the inflow of energy, minerals, and water. Organisms compete with one another for finite resources. As any population of organisms grows, it is held in check by one or more environmental factors, such as lack of resources, increased predation, or lack of nesting sites. Organisms can only survive in environments where their basic needs are met. NSES C4a
Specific Ideas	In all environments- freshwater, marine, forest, desert, grassland, mountains, and others- organisms with similar needs may compete with one another for resources, including food, space, water, air, and shelter. Benchmarks 5D1 Some resources are renewable, and some are finite. Renewable resources are ones that are replenished by cycles in the ecosystem as fast as (or faster than) they are removed. A population consists of all individuals of a species that occur together at a given place and time. All populations living together and the physical factors with which they interact compose an ecosystems. NSES C4a Lack of resources and other factors, such as predation and climate, limit the growth of populations in specific niches in the ecosystem. NSES C4d The output from one part of a system can become the input for another part of it. Benchmarks 11A2 When an area becomes overpopulated, the environment can become degraded due to the increased use of resources.
Developmental & Instructional Implications	Students may believe that organisms are able to effect changes in bodily structure to exploit particular habitats, or that they respond to a changed environment by seeking a more favorable environment. Teachers should challenge the misconception that the ocean is a limitless resource and that humans are indestructible as a species.
Examples