Do we (humans) truly have free will?
This notion is called the "Dilemma of Determinism." As humans, we are not equipped to answer this question because we do not know if our actions are controlled by a causal chain of preceding events , or if we're truly free agents, capable of making decisions of our own volition. The debate between philosophers and scientists (for millennia), has been whether our actions are caused by determinism of indeterminism.
As plants adapted to the terrestrial environment, what trends occurred in the size of the sporophyte and gametophyte? How can these trends be explained?
In order to thrive in life on land, plants had to undergo many evolutionary modifications. The successful terrestrial life of plants depended on plants’ abilities to protect themselves from dessication, the ability to provide adequate nutrients without the aid of abundance of water, and the ability to modify reproduction without the aid of water. Nonvascular plants rely on the abundance of water and flagellated male gametes to reproduce, but plants living on land rely on sporophytes and gametophytes, in addition to other things. When plants began to adapt to terrestrial environments, the size of sporophytes began to increase while the size of gametophytes decreased. The increase in size of sporophytes is attributed to the facts that sporophytes became more important to the land survival. During this shift, gametophytes were reduced to small pollen grains that heavily rely on wind for fertilization, this change occurred for gametophytes because the need to swim through water in order to reach female gametophytes was no longer necessary.
Marathon runners can become dehydrated due to extreme physical activity. What types of fluids should they consume in order to rehydrate their cells?
In order to restore water balance to the cells, the runners need to consume hypotonic solutions. The water in the hypotonic solution will move from the blood, into the interstitial fluid, then into the cells. Plain water works well; also, sports drinks contain water and some electrolytes, but will still be hypotonic in relation to the cells of the body.