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.
Answer:
c. organisms are better adapted to an environment.
Explanation:
With natural selection the parent gives of a gene that is better suited for survival in an environment.
Answer: Only some of the organisms survive and reproduce.
Natural selection is a process of differential survival and reproduction in which organisms bearing favorable phenotypic traits survive in changing environmental conditions. Therefore, only some of the organisms survive and reproduce which have suitable phenotypic trait. For example a population of beetle bearing two colors red and green. The green colored beetles mimic the color of grass will remain undetected by birds and those with red color easily observed and detected by birds. Hence, only green beetles are favored for survival over red beetles.
