According to the fossil record found in these sedimentary layers, what conclusion can be drawn about animal life in general? a) animals did not move on to land until flowering plants evolved. b) vertebrates appeared in the oceans before they moved on to land. c) vertebrates evolved on land and in the oceans at about the same time. d) shelled animals and fish appeared in the oceans at about the same time.

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