Dinoflagellates are unicellular, marine protists. Dinoflagellates are bioluminescent, but only at night. During the day, they carry out photosynthesis similar to other autotrophs. At night, however,...

Dinoflagellates are unicellular, marine protists. Dinoflagellates are bioluminescent, but only at night. During the day, they carry out photosynthesis similar to other autotrophs. At night, however, they bioluminesce every time they are disturbed. They are often seen in the wakes of ships at night. While the reason for this bioluminescence is not fully understood, many scientists concur that it is a form of self-defense. If small fish begin to feed upon the protists, the protists will begin to bioluminesce. These flashes of light in the dark water can alert larger fish and draw them towards the small fish, upon which they prey. By making the small fish vulnerable, the dinoflagellates are able to protect themselves. Based on the information above, a researcher decides to design an experiment in which she is testing how long it takes for dinoflagellates to recover after different amounts of disturbance. She maintains 10 containers of dinoflagellates with similar temperature, salinity and pH water. The dinoflagellates are provided with 12 hours of sunlight and 12 hours of darkness every day. To mirror a disturbance event, she vigorously stirs the water in each container for varying amounts of time, measuring how long it takes for all bioluminescence to stop afterwards. The disturbance durations are as follows: 15 seconds, 30 seconds, 45 seconds, and 60 seconds. She has two samples at each disturbance level as well as two samples undergoing no disturbance. A. What is the independent variable? B. What is the dependent variable?