According to scientific evidence, earth’s earliest atmosphere lacked oxygen. over time, oxygen was added to the atmosphere. which statements explain how this change occurred and how it affected life on earth? choose all answers that are correct.
a. the addition of oxygen to the earth's atmosphere make possible the development of eukaryotic organisms, which need oxygen to carry out many of their life processes.

List two limitations of natural selection

The many volcanoes located along the edge of the pacific ocean make up the ring of fire. how does subduction play a role in the volcanic activity in the ring of fire?

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.