Recent biochemical evidence divides all organisms into three domains: Bacteria, Archaea, and Eukarya. Previously, Bacteria and Archaea were viewed as one group. Which statement best describes why Bacteria and Archaea have been placed into separate domains? Question 4 options: A Archaea do not resemble Bacteria when viewed under a microscope. B Archaea were found to contain organelles, separating them from Bacteria. C Bacteria live in extreme environments and Archaea do not. D. They have differences in the biochemical makeup of their cell walls.

Depending on the organism the number of in a cell may change

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.

Once an egg cell is fertilized by sperm, the cell then, as the embryo develops, it receives nourishment and eliminates wastes by transferring substances from its blood to its mother's blood. a. becomes a fetus immediately and exits the womb b. begins to divide and implants itself in the wall of the uterus c. remains in the uterus without dividing for several months d. travels back to the ovaries until the fetus is developed