A botanist who was studying a new plant ground up some of the leaf cells, then centrifuged the mixture. The organelles became fractionated such that the heavier fractions could produce ATP in the light, and the organelles in the light fraction could produce ATP in the dark. What do the fractions most likely contain? a. The lighter fractions contained more mitochondria.

b. The heavier fractions contained more peroxisomes.

c. The fractions contained more centrioles.

d. The lighter fractions contained more chloroplasts.

Aresearcher designed an investigation to test what effect eating different types of food would have on blood insulin levels. she selected 10 male subjects who were all 25 years of age and in good health. the experiment took place over 3 days. at 8: 00 a.m. on each day, the subjects ate a meal consisting of only 1 type of food. they had their blood insulin levels measured after consuming the meal. on day 1 they ate a high fat diet, on day 2 they ate a high protein diet, and on day 3 they ate a high sugar diel what is the independent variable in this experiment? a the age of the subjects b the blood insulin level c the type of food consumed d the time of day the meal was consumed