Questions 1-13 The picture below shows a pond ecosystem - McREL

The picture below shows a pond ecosystem. Use this picture and what you know about the things in it to
answer the question below.
Tell why it is important for dead animals and plants in the pond system to be broken down.
NAEP released item, grade 8

Scoring Guide
Score & Description
Complete
Student response demonstrates an understanding of the importance of decomposition in the pond
ecosystem.
Credited responses include:
a. Release of nutrients for other organisms.
b. The soil is fertilized.
c. Food is provided to plants.
Partial
Student response demonstrates some understanding of the importance of decomposition.
Credited responses include:
a. Decomposition is part of the food chain.
b. Keep pond from filling up with dead stuff.
c. Food is provided to animals.
Unsatisfactory/Incorrect
Student response demonstrates a lack of understanding of the importance of decomposition.
Complete - Student Response
Tell why it is important for dead animals and plants in the pond system to be broken down.
Scorer Comments:
Student response explains the process of decomposition by mentioning that broken down animals
and plants provide nutrients for the soil and by providing further steps along the food chain.
NAEP released item, grade 8

Tell why it is important for dead animals and plants in the pond system to be broken down.
Scorer Comments:
Student response explains the process of decomposition by mentioning that broken down animals
and plants provide nutrients for other living things.
Partial - Student Response
Tell why it is important for dead animals and plants in the pond system to be broken down.
Scorer Comments:
Student response mentions decomposition and that decomposition keeps dead things from
crowding the pond, but does not explain that decomposition adds nutrients to the pond ecosystem.
Tell why it is important for dead animals and plants in the pond system to be broken down.
Scorer Comments:
Student response mentions that the breaking down of dead things keeps them from crowding the
pond, but does not explain that the process adds nutrients to the pond ecosystem.
NAEP released item, grade 8

Unsatisfactory/Incorrect - Student Response
Tell why it is important for dead animals and plants in the pond system to be broken down.
Scorer Comments:
Student response mentions the possibility of disease spreading through the ecosystem.
Tell why it is important for dead animals and plants in the pond system to be broken down.
Scorer Comments:
Student response mentions an aesthetic issue: the odor of dead animals or plants.
2000 National Performance Results
Score
Percentage of Students
Unsatisfactory/incorre
ct 34%
Partial 50%
Complete 12%
Omitted 3%
Off task 1%
NAEP released item, grade 8

Note:
• These results are for public and nonpublic school students.
• Percentages may not add to 100 due to rounding.
The Fields of Science: Life Sciences (Sub content classification: Ecology)
Knowing and Doing Science : Conceptual Understanding
NAEP released item, grade 8

The Fields of Science
Life Sciences
This question measures basic knowledge and understanding of the following:
Knowing and Doing Science
Conceptual Understanding
Conceptual understanding includes the body of scientific knowledge that students draw upon when
conducting a scientific investigation or engaging in practical reasoning. Essential scientific concepts
involve a variety of information, including facts and events the student learns from both science
instruction and experiences with natural environment; and scientific concepts, principles, laws, and
theories that scientists use to explain and predict observations of the natural world.
NAEP released item, grade 8