hard · Enhanced ACT Science
A biologist grew identical algae cultures under a red lamp and under a blue lamp, keeping the measured light intensity equal, and found more growth under blue light. She concluded that algae grow best in blue light. A colleague noted that the blue lamp was newer and ran a few degrees warmer than the red lamp throughout the trial.
Which additional trial would best determine whether light color, rather than temperature, caused the difference in growth?
- Grow algae under green light using the older, cooler lamp
- Grow both cultures with each lamp held at the same temperature
- Repeat the blue-light trial using a denser starting culture
- Grow algae in complete darkness to establish a baseline growth rate
Sign up free to see the explanation and track your rank →
More Enhanced ACT Science practice
- An experimenter tests the effect of different light… In this experimental design, what is…
- What is the relationship?
- Based on the table, when the speed of the car doubles, the stopping distance:
- As the frequency of the waves increases, the wavelength:
- At any given temperature, the catalyst increases the reaction rate by what factor?
- Which soil type retains the LEAST amount of water?
- Which species has a higher population at Year 5?
- What is the pressure when the volume is 2.0 L?
All Science questions · Enhanced ACT study guide · Enhanced ACT glossary · Enhanced ACT flashcards