Question

the passage below describes an experiment. read the passage and then follow the instructions. dr. conley was the land manager for a prairie that had become overrun by unwanted grasses. these grasses crowded out other plants. dr. conley thought that she could use fire to remove the unwanted grasses and allow other plants to grow. but she didnt know how often the prairie should be burned. dr. conley marked off six plots within a large area of the prairie. she used carefully controlled fires to burn all of the plants in each plot. she burned three of the plots once a year for three years. she burned the other three plots twice a year for three years. a year after the last fire, dr. conley counted the number of unwanted grasses in each of the six plots. complete the sentence. in this experiment, the number of unwanted grasses was a dependent variable an independent variable

Explanation:

The independent variable is what the researcher manipulates (frequency of burning). The number of unwanted grasses is measured based on different burning frequencies. It depends on the frequency of burning, so it is a dependent variable.

Answer:

a dependent variable