Question 11
Marie investigates how pollutant substance Y affects river organisms A, B and C. Each of four beakers contains 100 mL river water and the same initial number of each organism. She adds different amounts of Y and counts survivors daily for one week.
| Beaker | Initial number of each A/B/C | Y (mL) | A, day 7 | B, day 7 | C, day 7 |
| --- | --- | --- | --- | --- | --- |
| 1 | 20 | 10 | 14 | 17 | 20 |
| 2 | 20 | 20 | 10 | 13 | 20 |
| 3 | 20 | 30 | 8 | 10 | 20 |
| 4 | 20 | 0 | 20 | 20 | 20 |
Which statements are correct?
I. Amount of Y is a dependent variable.
II. As Y increases, A decreases.
III. C may have an adaptation against Y.
IV. Beaker 1 is the control.
V. B declines in the same trend as A.
| Beaker | Initial number of each A/B/C | Y (mL) | A, day 7 | B, day 7 | C, day 7 |
| --- | --- | --- | --- | --- | --- |
| 1 | 20 | 10 | 14 | 17 | 20 |
| 2 | 20 | 20 | 10 | 13 | 20 |
| 3 | 20 | 30 | 8 | 10 | 20 |
| 4 | 20 | 0 | 20 | 20 | 20 |
Which statements are correct?
I. Amount of Y is a dependent variable.
II. As Y increases, A decreases.
III. C may have an adaptation against Y.
IV. Beaker 1 is the control.
V. B declines in the same trend as A.