Ecosystems

Summative Assessment

8th Grade

1.  In the ecosystem unit you were asked to look at statements and questions to determine if they can be answered scientifically. Over the last 10 years, the number of deer-related car accidents has doubled. People believe that the increase is caused by the rise in the local deer population. Is there a relationship between deer-related car accidents and the deer population?
Can the question above be answered scientifically? Yes No (circle one)
If you answered yes, explain how. If you answered no, explain why not.

This item measures the student’s ability to identify reasonable, relevant, and testable questions that can be answered through scientific investigations. *Teacher note – Student work indicates students may need reminders to focus on the question, not on establishing whether or not car accidents affect the deer population.

Criteria for a Correct Response:

  1. Student indicates “yes,” the question can be answered scientifically, and the student includes one of the following:

§  Collection and analysis of data.

§  Acquisition of evidence through proper sampling techniques.

  1. Student provides an appropriate method to support their position.

§  Look at deer-related traffic accidents over a period of time and compare it to deer population numbers over same period of time.

§  Sampling of the deer population in the same area of the accidents over a period time.

§  Compare deer populations from historical data and compare it to the reported traffic accidents during that same period of time.

§  Hunter information data (sampling technique) correlated to traffic accidents in that area caused by deer.

Code / Response
Complete Response
20 / Meets all of the criteria above.
21 / Responds “yes” and gives one accurate method/example from above or other plausible example.
29 / Any other completely correct response.
Partially Correct Response
10 / Responds “yes,” includes criteria 1, but omits 2.
11 / Responds “yes” but only includes one piece of evidence, i.e., collect deer population over a period of time only.
12 / Answers “no” but includes valid reasoning (see examples from criteria 2).
19 / Any other partially correct response.
Incorrect Response
70 / Responds “yes” but no appropriate scientific reasoning.
71 / Responds “no” but no appropriate scientific reasoning.
72 / Responds “yes” but describes relationship (increased deer = more accidents).
76 / Repeats the stem of the question.
79 / Any other incorrect response.
Non-Response
90 / Crosses out, erases, illegible, or impossible to interpret.
99 / Blank.
2.  Name two abiotic factors and describe the effect of each factor on the deer population.

This item measures the student’s ability to identify abiotic factors and to describe their effect on an organism’s population.

Criteria for a Correct Response:

  1. Student identifies at least two abiotic factors (sunlight, space/shelter, soil, water, temperature, oxygen).
  1. Student provides reasonable and accurate descriptions for the effect of these factors on the deer population. For example: drought conditions could indicate less food that would cause the deer to relocate.

Code / Response
Complete Response
20 / Meets both of the above criteria.
29 / Any other completely correct response.
Partially Correct Response
10 / Lists two appropriate abiotic factors but no or an inaccurate description of the interaction.
11 / Lists only one appropriate abiotic factor with accurate description.
12 / Lists one appropriate abiotic factor with accurate description and a second inappropriate factor (guns/cars).
13 / Lists two appropriate abiotic factors but supplies only one description.
19 / Any other partially correct response.
Incorrect Response
70 / Lists one abiotic factor with no accurate description.
71 / Lists biotic factors.
72 / Lists human controlled technologies (cars/guns) with descriptions as abiotic factors.
76 / Repeats stem of the question.
79 / Any other incorrect response.
Non-Response
90 / Crosses out, erases, illegible, or impossible to interpret.
99 / Blank.
3.  Identify two structures on a deer that give it an advantage for survival. Describe how each of these structures is an advantage.

This item measures the student’s ability to identify and describe how a specific structure has advantages for an organism in its environment.

Criteria for a Correct Response:

  1. Student identifies two specific structures that give the deer an advantage in its environment (antlers, fur, shape of hooves, shape/size of ears, coloration, etc.).
  1. Student accurately explains the advantage (examples: coloration for camouflage, antlers for defense/competition for mates, large ears for hearing predators, etc.).

Code / Response
Complete Response
20 / Meets both of the criteria above.
21 / Meets criteria and includes how the environment selects for certain traits.
29 / Any other completely correct response.
Partially Correct Response
10 / Identifies one structure only with an accurate explanation.
11 / Identifies two structures but only with one accurate explanation.
12 / Gives an advantage but does not identify the structures.
19 / Any other partially correct response.
Incorrect Response
70 / Identifies one or more structure but no explanation.
71 / Identifies an essential characteristic that is not an advantageous adaptation, for example having four legs is not an advantageous structure.
72 / Identifies behaviors (herding/fast running) instead of structures.
73 / Uses environmental factors instead of structures.
76 / Repeats stem of the question.
79 / Any other incorrect response.
Non-Response
90 / Crosses out, erases, illegible, or impossible to interpret.
99 / Blank.
4.  Draw a complete food web of a woodland/agricultural area of Delaware with at least 6 organisms, including the white-tailed deer. Remember to use arrows to show the source of and flow of energy through the system.

This item measures the student’s ability to identify and draw a model showing the interactions in an ecosystem that result from the transfer of energy from the sun to the producers to consumers and eventually to decomposers.

Criteria for a Correct Response:

  1. Student uses arrows to show the flow of energy from the sun through the ecosystem.
  1. Student identifies 6 organisms that constitute a web that includes producers, consumers, and decomposers found in a woodland and/or agricultural area of Delaware.

* Teacher Notes – diagram should show a web, not several food chains. Bears, wolves, mountain lions are acceptable consumers. Student work indicates that they ignore the role of the sun and decomposers in the food web.

Code / Response
Complete Response
20 / Meets both of the above criteria.
29 / Any other completely correct response.
Partially Correct Response
10 / Shows a food chain, including the sun, instead of a web, but the flow of energy is accurate and decomposers are included.
11 / Shows web, including the sun, but omits decomposers and energy flow is accurate.
12 / Shows a web, including the sun, but has 5 organisms and energy flow is accurate.
19 / Any other generally complete response.
Incorrect Response
70 / Shows web but does not have the correct flow of energy, i.e., the arrows are reversed or omitted.
71 / Omits the sun as the source of energy.
72 / Includes organisms not found in woodland/agriculture areas in Delaware such as elephants, tigers, or monkeys.
73 / Includes the sun but has fewer than 5 organisms in the web.
76 / Repeats the stem of the question.
79 / Any other incorrect response.
Non-Response
90 / Crosses out, erases, illegible, or impossible to interpret.
99 / Blank.
5.  Describe any patterns from either the lynx or the hare population graphs. See reference sheet.

This item measures the student’s ability to identify a pattern in a population.

Criterion for a Correct Response:

  1. Student describes any pattern in at least one of the graphs. Example: The hare population increases and then declines rapidly followed by a period where the population levels off. It then increases again declines rapidly again.

Code / Response
Complete Response
20 / Meets above criteria.
29 / Any other completely correct response.
Partially Correct Response
10 / Incomplete description of pattern, for example “Hare population went up from 1900 to 1903.”
11 / Description of predator/prey relationship, for example “As lynx population increases, hare population decreases.”
19 / Any other partially correct response.
Incorrect Response
70 / States incorrect pattern, for example “Hares decrease from 1900 to 1902.”
71 / States specific data points.
76 / Repeats the stem of a question.
79 / Any other incorrect response.
Non-Response
90 / Crosses out, erases, illegible, or impossible to interpret.
99 / Blank.
6.  What might be a possible cause for the pattern you described in question number 5? Support your answer with an explanation.

This item measures the student’s ability to identify and describe plausible explanations for a pattern in a population graph.

Criterion for a Correct Response:

  1. Student will provide a plausible reason for the pattern. Example: The hare population increases rapidly while there is low predator pressure. The hare population peaks and rapidly declines when predator stress increases. (Disease, carrying capacity, hunting etc., are viable explanations.)

Code / Response
Complete Response
20 / Meets above criteria.
29 / Any other completely correct response.
Partially Correct Response
10 / Gives a reason with no explanation for pattern, for example “The lynx eat the hares.”
19 / Any other partially correct response.
Incorrect Response
70 / Incorrect explanation of pattern, for example “seasonal changes.”
76 / Repeats the stem of a question.
79 / Any other incorrect response.
Non-Response
90 / Crosses out, erases, illegible, or impossible to interpret.
99 / Blank.
7.  When your neighbor learned that you were studying horseshoe crabs in school, he made the following statement: Who cares about the horseshoe crabs? The crabs are here for people to use however we want. Take a position either for or against your neighbor’s statement. Use the data supplied in the tables (see reference sheet) and what you learned from the Ecosystems unit to support your argument.

This item measures the student’s ability to evaluate human impact on an ecosystem and defend a position using data and previous learning.

Criteria for a Correct Response:

  1. Student will clearly declare a position in agreement or refuting the neighbor.
  1. Student uses appropriate concepts from the unit and/or data from the tables in order to support their position. (Example: Topics might include biomedical research, eggs are food for the shorebirds, waterman’s livelihood, etc.)

Code / Response
Complete Response
20 / Meets above criteria.
21 / Meets criteria and uses other valid data not listed.
29 / Any other completely correct response
Partially Correct Response
10 / Takes a position but supports with “weak” reasons, for example “they are old,” “they are important to shorebirds.”
11 / Gives valid reasoning for a particular view but does not state a position for or against.
12 / Argues both sides of the argument logically but does not commit to a position.
19 / Any other generally complete response.
Incorrect Response
70 / Takes a position but does not explain why or use data from tables.
76 / Repeats stem of question.
79 / Any other incorrect response.
Non-Response
90 / Crosses out, erases, illegible, or impossible to interpret.
99 / Blank.

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