Question

1. which factor was varied in experiment 1? a basin surface area b. algae growth rate c. algal blooms per square meter d. water temperature 2. experiment 1 differed from experiment 2 in that experiment 2: f did not fertilize basin b with phosphorus. g did not fertilize basin a with phosphorus. h did not fertilize basin a with sodium bicarbonate. j fertilized basin b with carbon and nitrogen only. 3. suppose that extensive algal blooms cause pollution problems and that detergents are a major source of phosphorus in fresh water. to reduce the pollution associated with algal blooms, it would be most useful to: a. increase the amount of detergent present in fresh water. b. decrease the amount of detergent present in fresh water. c. replace the phosphorus in detergents with sodium bicarbonate. d. balance the phosphorus added to detergents with equal amounts of sodium bicarbonate. 4. based on the results of experiments 1 and 2, which of the following bodies of water is likely to produce the greatest number of algal blooms per square meter? f. a 45°c pond fertilized with sodium bicarbonate g. a 5°c pond fertilized with sodium bicarbonate h. a 45°c pond fertilized with phosphorus j. a 5°c pond fertilized with a mixture that is equal parts phosphorus and sodium bicarbonate 5. the experimenters chose to modify the fertilizers added to basin a between the two experiments without changing those added to basin b. which of the following statements gives the most likely reason the experimenters made that choice? the experimenters: a. wanted to use the same control for both experiments. b. wanted to test variations in the amount of fertilizer used. c. wanted to confirm the results from experiment 1. d. did not have another fertilizer to test. 6. suppose that basin a had not been fertilized with carbon and nitrogen in experiment 2. at the conclusion of their two years of testing, the experimenters would not have been able to: f. measure the effect of sodium bicarbonate on algae growth. g. measure the effect of phosphorus on algae growth. h. measure the effect of carbon and nitrogen alone on algae growth. j. measure the effect of temperature on algae growth.

Explanation:

1. In experiment - related questions, we look for the variable being manipulated. Usually, factors like temperature can be varied in an experiment.
2. Comparing two experiments, we note differences in fertilization of basins.
3. To reduce pollution from algal blooms, we consider the source of pollution (phosphorus in detergents).
4. We analyze the impact of temperature and fertilizer on algal bloom density.
5. Keeping one basin's fertilizer constant while changing the other's is related to having a control.
6. Omitting a certain fertilizer in an experiment affects what can be measured.

Answer:

1. D. Water temperature
2. G. did not fertilize Basin A with phosphorus.
3. B. decrease the amount of detergent present in fresh water.
4. H. A 45°C pond fertilized with phosphorus
5. A. wanted to use the same control for both experiments.
6. H. measure the effect of carbon and nitrogen alone on algae growth.