Writing on the exam will incur a 10 point penalty. After you obtain your degree in biology you get a job as a laboratory technician for an introductory biology course at a large university. The first lab in this course involves an experiment in optical orientation in blowfly larvae. When the larvae arrive the day before lab, you are horrified to find them all dead. Using quick thinking, you run down to the local bait shop for wax worms.
Wax worms are unsuitable subjects for optical orientation experiments.
The worms display a negative phototaxic response to green light. The worms display a positive phototaxic response to green light. The worms display a positive phototaxic response to red light. You have proven that wax worms prefer green light to red light. The majority of the time, the worms headed toward green light which is a positive phototaxic response.