To answer this question, we'll analyze the data provided in the table, which shows the number of contractions per minute of the Paramecium contractile vacuole under different salt concentrations outside the organism.
First, let's review the data given:
1. Very high salt concentration: 2 contractions per minute
2. High salt concentration: 8 contractions per minute
3. Medium salt concentration: 15 contractions per minute
4. Low salt concentration: 22 contractions per minute
5. Very low salt concentration: 30 contractions per minute
Now, let’s evaluate each statement:
1. The graph has five bars of equal height.
- This is incorrect because the number of contractions per minute varies for each salt concentration level.
2. The bars range from tallest for very high concentration to shortest for very low concentration.
- This is incorrect as well; the number of contractions increases as the salt concentration decreases.
3. The bar for very low concentration is twice the height of the bar for medium concentration.
- We check the ratio of contractions at very low concentration to medium concentration:
[tex]\( \frac{30}{15} = 2.0 \)[/tex]
- This statement is correct because the number of contractions per minute for very low concentration (30) is indeed twice that of medium concentration (15).
4. The bar for very high concentration is five times the height of the bar for very low concentration.
- We check the ratio of contractions at very high concentration to very low concentration:
[tex]\( \frac{2}{30} = \frac{1}{15} \approx 0.0667 \)[/tex]
- This statement is incorrect because the ratio is roughly 0.0667, meaning that the bar for very high concentration is significantly shorter, not five times taller.
Therefore, the correct statement is: The bar for very low concentration is twice the height of the bar for medium concentration.
