Why are the proteins at the "very heart" of life

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.

{answer found. it's (3 ) }which statement describes the cell cycle? (1)the cell cycle is a process in which one cell divides into four genetically different cells. (2)the cell cycle is a process in which one cell divides into two genetically different cells. (3)the cell cycle is a process in which one cell divides into two genetically identical cells. (4)the cell cycle is a process in which one cell divides into four genetically identical cells.

What best explains the inability for life to exist in earth early atmosphere