The circulatory system will make the heart pump faster, moving blood, oxygen, and nutrients around the body. the excretory system will excrete waste like sweat through the skin, maintaining a steady body temp.
Answer: D. Hypothesis B is more useful because it suggests a way to test the relationship between heart rate and caffeine intake.
Hypothesis A and B both are suggesting that caffeine intake is related to higher heart rate. But hypothesis B is proving it more certainly by suggesting the affects of caffeine intake on heart rate. As, heart rate of most people will be higher 30 minutes after they drink a cup of coffee is testifying the fact, that higher heart rate is related with caffeine intake.
Therefore, hypothesis B is more useful because it suggests a way to test the relationship between heart rate and caffeine intake.
The answer to the question mentioned above is the "Chloroplast".
During the light-dependent reaction of photosynthesis, chloroplast is decomposed to supply hydrogen ions tp produce NADPH, and important energy-carrying molecule used to help produce glucose during the light dependent reaction.
<span>I usually think of biology first, and then physics. I trust those types of science a whole lot more than social sciences. I don't think of it like most non-sciency people do (like with diet pills and perfume). I think of it like using the actual scientific method, doing the same thing over and again expecting different results, taking the objective (or subjective, when that applies) results and forming a logical conclusion and not one that fits your hypothesis/agenda. Kind of like those kids that every high school has (on TV shows, they're the ones that are doing something with robotics all the time) that are nerdy, science geeks always running experiments and seeing what happens. </span>