Item EM051002: Lactase activity varies among individuals in the population. (Recognize a graph that represents that variability.)
Lactase is an enzyme that helps digest milk. All human infants make lactase, but some individuals make less of it by the time they reach adolescence. A person’s lactase activity is measured in units (U).
Below is a graph that shows the lactase activity of adults in a population.
Which of the following claims is supported by this graph?
- Lactase activity is changing over time in the population.
- Lactase activity varies among individuals in the population.
- Lactase activity is undergoing natural selection in the population.
- Lactase activity is the same throughout the population.
Pre-Test
Answer Choice |
Overall |
Grades |
Gender |
Primary Language |
||||
|---|---|---|---|---|---|---|---|---|
| n = 580 |
6–8 n = 25 |
9–12 n = 514 |
Male n = 254 |
Female n = 286 |
English n = 526 |
Other n = 13 |
||
| A. | Lactase activity is changing over time in the population. | 20% | 16% | 20% | 24% | 17% | 20% | 46% |
| B. | Lactase activity varies among individuals in the population. | 70% | 64% | 70% | 67% | 73% | 71% | 46% |
| C. | Lactase activity is undergoing natural selection in the population. | 10% | 20% | 9% | 9% | 9% | 10% | 8% |
| D. | Lactase activity is the same throughout the population. | 0% | 0% | 0% | 0% | 0% | 0% | 0% |
Post-Test (Control)
Answer Choice |
Overall |
Grades |
Gender |
Primary Language |
||||
|---|---|---|---|---|---|---|---|---|
| n = 255 |
6–8 n = 15 |
9–12 n = 195 |
Male n = 97 |
Female n = 119 |
English n = 205 |
Other n = 6 |
||
| A. | Lactase activity is changing over time in the population. | 21% | 27% | 18% | 19% | 20% | 20% | 17% |
| B. | Lactase activity varies among individuals in the population. | 68% | 53% | 70% | 68% | 69% | 70% | 17% |
| C. | Lactase activity is undergoing natural selection in the population. | 10% | 20% | 10% | 13% | 9% | 10% | 50% |
| D. | Lactase activity is the same throughout the population. | 1% | 0% | 1% | 0% | 2% | 0% | 17% |
Post-Test (Treatment)
Answer Choice |
Overall |
Grades |
Gender |
Primary Language |
||||
|---|---|---|---|---|---|---|---|---|
| n = 301 |
6–8 n = 8 |
9–12 n = 274 |
Male n = 134 |
Female n = 150 |
English n = 274 |
Other n = 9 |
||
| A. | Lactase activity is changing over time in the population. | 13% | 0% | 13% | 11% | 14% | 13% | 0% |
| B. | Lactase activity varies among individuals in the population. | 75% | 100% | 74% | 74% | 75% | 74% | 89% |
| C. | Lactase activity is undergoing natural selection in the population. | 12% | 0% | 13% | 15% | 11% | 13% | 11% |
| D. | Lactase activity is the same throughout the population. | 0% | 0% | 0% | 0% | 0% | 0% | 0% |