The excerpt is from an article that Roberto read for science class called “Using the Scientific Method to Study Tomatoes.” The student performed an experiment to test his hypothesis about sunlight and plant height using two plants. He kept everything the same between two tomato plants except he exposed them to different amounts of sunlight. He also used a third plant as a control group, or a group in which no variables are manipulated to confirm the results.
Roberto critiqued the work. Which problem did Roberto most likely identify?
The sample size is too small.
Too many variables are manipulated.
It is not possible to keep the conditions the same.
Controls should only be used in studies of animals.

The sample size is too small.

Explanation:

The process of elimination helped me find this answer.

It is possible to keep the conditions the same.

there are only 2 plants and one control, that's obviously not a lot.

and controls can be used on more than studying animals.

When using the scientific method you can use as many test subjects as you can so it can help you confirm. two plants are not a lot.

I've also had a teacher confirm that this is the correct answer.

edge 2020

1. a host loses nutrients to a parasite

2. a parasite only benefits when the host is alive (cause if the host dies the parasite dies with it )

3. producers to consumers

4. the tapeworm is a parasite

5. they convert energy from the sun (photosynthesis)

6. sunflower-robin (i think im 80% sure)

7. producer

8. consumer

9. prey

10. fresh water snails ( cause the green algea is the producer and the snails are the primary consumers and the small fish consumer so is the big fish)