In this 40-minute extended task, students use a simulated greenhouse to determine the best sunlight or fertilizer amounts for two different plants. Students begin the task by showing their prior knowledge about how sunlight and nutrients are related to optimal plant growth. Then students run three separate investigations and draw their conclusions about the effect of sunlight and nutrients on the plant samples.

Below are the questions, your answers, and the scoring criteria for each of the questions in this task. Use the navigation on the left to return to browsing the site or to take another task.

How much sunlight do plants need to grow well?

Choose the statement below that you think is most likely true.

A. Most plants need only a little sunlight to grow well.
B. The more sunlight plants get, the better they grow.
C. Sunlight does not affect how most plants grow.
D. Different kinds of plants need different amounts of sunlight to grow well.

Your answer:  

Correct answer:  Different kinds of plants need different amounts of sunlight to grow well.

How much fertilizer do plants need to grow well?

Choose the statement below that you think is most likely true.

A. Different kinds of plants need different amounts of fertilizer to grow well.
B. Fertilizer does not help most plants grow well.
C. The more fertilizer you give plants, the better they will grow.
D. A little fertilizer will make most plants grow best.

Your answer:

Correct answer: Different kinds of plants need different amounts of fertilizer to grow well.

Based on your observations and the results in the data table shown above, which information about the plant will tell you if the plant is healthy or unhealthy? (Choose all that apply.)

1. Color of leaves
2. Number of flowers
3. Number of leaves
4. Height of plant

Your answer:

Correct answer: Number of flowers and number of leaves

Student responses were scored as follows:

• Students with both correct answers were scored as a three.
• Students with one correct answer were scored as a two.
• Students with no correct answers were scored as a one.

Please predict how much sunlight Plant A will need to grow best.

A. Lots of sunlight.
B. Some sunlight.
C. A little sunlight.
D. It will grow the same no matter how much sunlight it gets.
E. You can't tell. Different kinds of plants need different amounts of sunlight.

Your answer:

Correct answer: You can't tell. Different kinds of plants need different amounts of sunlight.

Part 1: Sunlight Investigation

To determine if the best possible experiments were run for Part 1 (based on experiments run prior to confirming “Next to continue”):

4: Run experiments using two trays on each greenhouse shelf.
3: Run experiments using at least one tray on each shelf but not two trays on each shelf.
2: Run experiments using at least one tray on two different shelves. One shelf remains empty.
1: Run experiments using any number of trays on only one shelf.

Number of trays you moved:

Minimum number of trays needed to collect sufficient data: three, one on each shelf.

Based on your experiments and the results in the data table, how much sunlight does Plant A need to grow best?

You may look at your data table again to help you with your answer.

• Lots of sunlight
• Some sunlight
• A little sunlight

Your answer:

Correct answer: Lots of sunlight

Support your answer with specific observations and results from the data table.

Type your answer in the box.

Your answer:

Sample Complete Student Response: When plant A grew in lots of sunlight it had more flowers and leaves than in some sunlight and a little sunlight.

Scoring guide

Complete:
Student response selects "Lots of Sunlight" and supports this conclusion using results of the investigation. The explanation is based on the data table or the student’s observations and refers to the number of leaves and/or flowers. The explanation is comparative.

Essential:
Student response selects "Lots of Sunlight" and supports this conclusion using results of the investigation. The explanation is based on the data table or the student’s observations, but is general and does not refer to the number of leaves and/or flowers. The explanation is comparative.

Partial:
Student response selects "Lots of Sunlight" and supports this conclusion using results of the investigation. The explanation provides some correct interpretation of the data regarding the growth of plants, but does not compare the growth of plants in Lots of Sunlight to the growth of plants in other light conditions.

OR

Student response selects "Some Sunlight" or "A Little Sunlight" and supports this conclusion using results of the investigation. The explanation provides some correct interpretation of the data.

Unsatisfactory/Incorrect:
Student response is inadequate or incorrect.

Plant B is a different kind of plant than Plant A. Please predict how much sunlight Plant B needs to grow best.

A. Lots of sunlight.
B. Some sunlight.
C. A little sunlight.
D. It will grow the same no matter how much sunlight it gets.
E. You can’t tell. Different kinds of plants need different amounts of sunlight.

Your answer:

Correct answer: You can’t tell. Different kinds of plants need different amounts of sunlight.

Part 2: Sunlight Investigation

To determine if the best possible experiments were run for Part 2 (based on experiments run prior to confirming “Next to continue”):

4: Run experiments using two trays on each greenhouse shelf.
3: Run experiments using at least one tray on each shelf but not two trays on each shelf.
2: Run experiments using at least one tray on two different shelves. One shelf remains empty.
1: Run experiments using any number of trays on only one shelf.

Number of trays you moved:

Number of trays needed to have used to collect sufficient data: a minimum of three, one on each shelf.

Based on your experiments and the results in the data table, how much sunlight does Plant B need to grow best?

You may look at your data table again to help you with your answer.

• Lots of sunlight
• Some sunlight
• A little sunlight

Your answer:

Correct answer: A little sunlight.

Support your answer with specific observations and results from the data table.

Type your answer in the box.

Your answer:

Sample Complete Student Response: Plant B needs a little sunlight to grow best. In lots of sunlight there was very few flowers and leaves. In some sunlight there was some flowers and leaves. In a little sunlight there were the most flowers and leaves. Therefore it grew the best.

Scoring guide

Complete:
Student response selects "A Little Sunlight" and supports this conclusion using results of the investigation. The explanation is based on the data table or the student’s observations and refers to the number of leaves and/or flowers. The explanation is comparative.

Essential:
Student response selects "A Little Sunlight" and supports this conclusion using results of the investigation. The explanation is based on the data table or the student’s observations, but is general and does not refer to the number of leaves and/or flowers. The explanation is comparative.

Partial:
Student response selects "A Little Sunlight" and supports this conclusion using results of the investigation. The explanation provides some correct interpretation of the data regarding the growth of plants, but does not compare the growth of plants in A Little Sunlight to the growth of plants in other light conditions.

OR

Student response selects "Lots of Sunlight" or "Some Sunlight" and supports this conclusion using results of the investigation. The explanation provides some correct interpretation of the data.

Unsatisfactory/Incorrect:
Student response is inadequate or incorrect.

One of your classmates looks at the results of your experiments with Plant B. She concludes: “Plants need sunlight so the more sunlight plants get, the better they grow.” Is your classmate's conclusion correct?

o Yes
o No

Your answer:

Support your answer with specific observations and results from the data table.

Type your answer in the box.

Explain your answer:

Sample Complete Student Response: 

No. All of the plant B's are very tall. But when plant B was in a little sunlight it had the most flowers and leaves.

Scoring Guide

Complete:
Student response selects "No" and supports this conclusion using results of the investigation. The explanation is based on the data table or the student’s observations and refers to the number of leaves and/or flowers. The explanation is comparative.

Essential:
Student response selects "No" and supports this conclusion using results of the investigation. The explanation is based on the data table or the student’s observations, but is general and does not refer to the number of leaves and/or flowers. The explanation is comparative.

Partial: Student response selects "No" and supports this conclusion using results of the investigation. The explanation shows some correct interpretation of data, but does not compare the growth of plants in different light conditions.

OR

Student response selects "Yes," but does not support this conclusion. The explanation provides information from specific observations and/or results from the data table.

Unsatisfactory/Incorrect:
Student response is inadequate or incorrect.

One of your classmates makes a prediction about what you will learn from this experiment. He says: "Plants need nutrients to grow. So, the more fertilizer Plant A gets, the better Plant A will grow.”

Do you agree with your classmate's prediction?

o Yes
o No

Your answer:

Explain your answer. Type your answer in the box.

Explain your answer:

Sample Complete Student Response: 

No. I don't think the classmates answer is correct because from my experience at home, if you put too much fertilizer, the plant will die.

Scoring Guide

Complete: 

Student response selects "No" and provides a complete explanation that consists of two parts:
• The anticipated effect of fertilizer on plant growth
• The cause of the anticipated effect of fertilizer on plant growth

For example, adding too much fertilizer may harm the plant, or different plants need different amounts of fertilizer to grow.

Partial:
Student response selects "No," addresses one part of a complete explanation.

OR

Student response selects "Yes" and provides an explanation that demonstrates an understanding that plants need nutrients as food to grow or includes the anticipated effect of fertilizer on plant growth and the cause of that effect.

Unsatisfactory/Incorrect:
Student response is inadequate or incorrect.

Part 3 Fertilizer Investigation

Did student use strategic levels of fertilizer?

Number of strategic groups you used:

Number of strategic groups you used to determine optimal fertilizer level: Includes at least 1 scoop level from each of three groups:

Group 1 - 1, 2, or 3
Group 2 - 4, 5, or 6
Group 3 - 7, 8, or 9

Part 3 Fertilizer Investigation

Did student use optimal fertilizer level in experiments?

Number of scoops you used in the experiments:

Number of scoops used to determine optimal fertilizer level: Used 3 scoops and either 2 or 4 scoops or both

How many scoops of fertilizer does Plant A need to grow best?

You may look at your data table again to help you with your answer.

- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9

Your answer:

Scoring guide

Complete:
Response of 3

Partial:
Response of 2 or 4

Unsatisfactory/Incorrect:
Response of 1, 5, 6, 7, 8, or 9

Remember that your classmate said: "Plants need nutrients to grow. So the more fertilizer Plant A gets, the better Plant A will grow." Now that you have finished your experiments with Plant A and fertilizer, do you agree with your classmate?

o Yes
o No

Your answer:

Support your answer with specific observations and results from the data table.

Type your answer in the box.

Your answer:

Sample Complete Student Response: 

No. When I tried adding 9 cups of fertilizer, Plant A didn't grow a lot. When there was only 3 cups of fertilizer, Plant A had a lot more flowers and leaves.

Scoring guide

Complete:
Student response selects "No" and supports this conclusion using results of the investigation. The explanation provides specific results from the data table or observations of plant growth to show that more nutrients do not necessarily result in better plant growth. The response compares results of using more and less fertilizer.

Partial:
Student response selects "No" and supports this conclusion using results of the investigation. The explanation provides specific results from the data or observations of plant growth to show that more nutrients do not necessarily result in better plant growth. The response does not compare results of using more and less fertilizer.

OR

Student response selects "Yes" and supports this conclusion using results of the investigation. The explanation provides specific results from the data table or observation of plant growth to show that more nutrients result in better plant growth. The response may or may not compare results of using more and less fertilizer.

Unsatisfactory/Incorrect:
Student response is inadequate or incorrect.

Based on your experiments in Parts 1, 2, and 3, which statement is most likely true?

A. Most plants need some shade and some nutrients to grow well.
B. Most plants need direct sunlight and some nutrients to grow well.
C. Different kinds of plants need different amounts of sunlight and nutrients to grow well.
D. The more sunlight and nutrients plants get, the better they grow.

Your answer:

Correct answer: Different kinds of plants need different amounts of sunlight and nutrients to grow well.

SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2009 Science Assessment.