About a billion years ago, the first complex cell is thought to have evolved by the fusion of two
cells. This is the Endosymbiotic Theory and two organelles found in eukaryotes to support this
theory of evolution are chloroplasts and mitochondria. What was thought to be the host cell?
a. Nucleus
b. Cell membrane
C. Protista
d. Archaea bacterium.

Which of the following correctly list the first appearance of organism in the fossil record from earliest to most recent

The buildup of sediments where a river empties into a slow-moving or nonmoving body of water is known as a/an

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.