Many plants can grow in the littoral zone of a lake because a. sunlight reaches its bottom. b. there are no algae. c. there are no animals. d. there is both salt water and fresh water.

In which situations is the principle of cross-cutting relationship useful in determining relative age?

Sperm pass through the and connect to a short ejaculatory duct. vas deferens prostrates seminiferous tubules none of the above

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