Students in a college made this hypothesis: ‘reaction time will increase as the time you have been awake increases.’ The students set up an investigation to test their hypothesis. This is the method used. 1. Find 5 volunteers willing to stay awake for 24 hours. 2. Keep the volunteers in a room where they can study, use an exercise bike or watch TV as they wish. 3. Provide food, water, coffee and tea as requested. 4. Measure the volunteers’ reaction time every 4 hours using a computer program. (b) What was the independent variable in this investigation?

Time one has been awake

Explanation:

In research, the independent variable is the one that is altered to see the effect that it produces on another variable/s which will be the dependent variable/s.

In this scenario, the amount of time that someone stays awake is the variable being altered to see what effect it will have on the person's reaction time. This therefore makes it the independent variable.

2%? i tried finding the exact sorry if it's not 100% correct ; -;

photosynthesis makes the glucose that is used in cellular respiration to make atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.