The famous scientist albert einstein sometimes used "thought experiments" such as imagining himself chasing a beam of light or riding in an elevator in free-fall. these thought experiments, which would not be possible to conduct physically, him challenge current scientific thinking and develop his theories of gravity and of special relativity.

Which of the following describes a negative feedback loop? when the heart rate is too high, the body sends hormones that continually increase the heart rate higher. when a pregnant woman is in labor, the body sends hormones that increase the intensity of contractions, which then increases the secretion of the same hormones. when blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows. when a person is jogging, the body sends hormones that continually decrease the rate of oxygen supply to the legs.

Guard cells control which event? the growth of plants capture of solar energy gas exchange in leaves water absorption in roots

Explain how sequences of amino acids in proteins can be used to reveal relationships among organisms.