Problem Analysis:
The image provided shows an experimental setup where two plants are being tested under different conditions. One plant is given fertilizer, while the other is not. Both plants receive the same amount of water (200 mL). The goal is to analyze the experiment and answer the questions based on the diagram.
#### Key Elements in the Diagram:
1.
Plant 1: Receives 10 mL of fertilizer.
2.
Plant 2: Does not receive any fertilizer.
3. Both plants receive 200 mL of water.
4. The variable being manipulated is the presence or absence of fertilizer.
Question 1: Which question is being tested?
The diagram shows that the only difference between the two plants is the addition of fertilizer. Therefore, the experiment is designed to test the effect of fertilizer on plant growth. Let's evaluate each option:
-
Option a: "Do flowering plants grow taller when watered with salt water?"
- This is not being tested because there is no mention of salt water in the diagram. Both plants are watered with regular water.
-
Option b: "Does adding fertilizer cause flowering plants to grow taller?"
- This matches the setup. One plant receives fertilizer, and the other does not. The experiment aims to observe if the addition of fertilizer affects plant height.
-
Option c: "How much fertilizer do flowering plants need to grow taller?"
- While this is related, the experiment only tests the presence or absence of fertilizer, not different amounts of fertilizer.
-
Option d: "What is the best kind of fertilizer that a gardener can give a flowering plant?"
- This is not being tested because there is no variation in the type of fertilizer; only its presence or absence is considered.
Correct Answer:
b. Does adding fertilizer cause flowering plants to grow taller?
Question 2: Write change, responding, and control variables.
To answer this, we need to identify the variables in the experiment:
#### a. The size of the pot
-
Change Variable: This is not a variable being manipulated in the experiment. Both plants are in pots of the same size. Therefore, it is a
control variable.
-
Control: The size of the pot is kept constant to ensure that any differences in plant growth are due to the fertilizer and not the pot size.
#### b. The kind of potting soil
-
Change Variable: This is also not a variable being manipulated in the experiment. Both plants are likely using the same kind of potting soil. Therefore, it is a
control variable.
-
Control: The kind of potting soil is kept constant to ensure that any differences in plant growth are due to the fertilizer and not the type of soil.
Final Answers:
1.
b. Does adding fertilizer cause flowering plants to grow taller?
2.
-
a. The size of the pot: Control
-
b. The kind of potting soil: Control
Boxed Final Answer:
\[
\boxed{b}
\]
Parent Tip: Review the logic above to help your child master the concept of scientific variables worksheet.
