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TKI Biology Assessment Resources

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For Excellence, the student needs to demonstrate comprehensive understanding of how an animal maintains a stable internal environment.

This involves producing evidence that builds on in-depth understanding to show the linking of biological ideas about maintaining a stable internal environment in an animal, see Explanatory Note (EN) 4.

The student needs to produce evidence that includes at least one of:

• a discussion of the significance of the control system (EN3) in terms of its adaptive advantage
• an explanation of the biochemical and/or biophysical processes underpinning the mechanism
• an analysis of a specific example of how external and/or internal environmental influences result in a breakdown of the control system.

This student has described and explained the purpose (1), components (2) and the mechanism (3) of osmoregulation in Chinook salmon. Biological ideas are used to explain how a specific disruption like water-borne toxicants (4) results in stress responses to re-establish a stable internal environment (5).

Evidence of a discussion of biological ideas linking the significance of osmotic balance in terms adaptive advantage has been explicitly shown (5). This is supported by an explanation of the biochemical and biophysical processes underpinning the osmoregulatory mechanism in Chinook salmon, which ensures completion of the requirement.

For Merit, the student needs to demonstrate in-depth understanding of how an animal maintains a stable internal environment.

This involves using biological ideas, see Explanatory Note (EN) 4, to explain how or why an animal maintains a stable internal environment. It includes explaining how a specific disruption results in responses within a control system (EN3) to re-establish a stable internal environment.

This student has provided evidence to describe and explain the purpose (1), components (2) and the mechanism (3) of osmoregulation in Chinook salmon. Biological ideas are used to explain how a specific disruption results in responses to re-establish a stable internal environment (4). The student begins to link biological ideas on the significance of osmoregulation in terms of its adaptive advantage (5).

This evidence does not reach Excellence because more depth is expected for a discussion linking biological ideas on the significance of osmotic balance in terms of its adaptive advantage.

For Merit, the student needs to demonstrate in-depth understanding of how an animal maintains a stable internal environment.

This involves using biological ideas, see Explanatory Note (EN) 4, to explain how or why an animal maintains a stable internal environment. This includes explaining how a specific disruption results in responses within a control system (EN3) to re-establish a stable internal environment.

This student has described and explained the purpose (1), components (2) and the mechanism (3) of osmoregulation in Chinook salmon.

Some biological ideas are used to describe and explain how a specific disruption results in responses to re-establish a stable internal environment (4).

For a more secure Merit, the student could use biological ideas to give a more in-depth explanation of:

• the mechanism of osmoregulation in Chinook salmon
• how a specific disruption results in responses within a this control system to re-establish a stable internal environment.

For Achieved, the student needs to demonstrate understanding of how an animal maintains a stable internal environment.

This involves using biological ideas, see Explanatory Note (EN) 4, to describe a control system (EN3) by which an animal maintains a stable internal environment.  Annotated diagrams or models may be used to support the description.

This student has described and partly explained the purpose (1), components (2) and the mechanism (3) of osmoregulation in Chinook salmon.

Some biological ideas are used to describe and partly explain how a specific disruption results in responses to re-establish osmotic balance (4).

To reach Merit, the student could use biological ideas to explain in more depth:

• how or why an animal maintains a stable internal environment to regulate osmotic balance
• how a specific disruption results in responses within this control system to re-establish a stable internal environment.

For Achieved, the student needs to demonstrate understanding of how an animal maintains a stable internal environment.

This involves using biological ideas, see Explanatory Note (EN) 4, to describe a control system (EN3) by which an animal maintains a stable internal environment.  Annotated diagrams or models may be used to support the description.

This student has described the purpose (1) and components (2) of  osmoregulation in Chinook salmon.

Some biological ideas are used to describe the mechanism of (3), and disruption to this control system (4).

For a more secure Achieved, the student could use biological ideas to give a more detailed description of  the:

• feedback mechanism of osmoregulation in Chinook salmon.
• potential effect of disruption to this control system by internal or external influences.

For Achieved, the student needs to demonstrate understanding of how an animal maintains a stable internal environment.

This involves using biological ideas, see Explanatory Note (EN) 4, to describe a control system (EN3) by which an animal maintains a stable internal environment.  Annotated diagrams or models may be used to support the description.

This student has demonstrated limited understanding by describing the purpose (1) and components (2) of osmoregulation in Chinook salmon.

Some biological ideas are briefly considered to describe the mechanism of (3), and disruption to this system (4).

To reach Achieved, the student could use biological ideas to give a more thorough description of:

• the purpose, components and mechanism of osmoregulation in Chinook salmon.
• a specific disruption results in responses within this control system to re-establish a stable internal environment.