I would believe a. prophase
Answer:
I think the difference between Charophyta and Chlorophyta is that Charophyta forms a paraphyletic group.
Explanation:
B) Embryonic stem cells research requires the use of human embryos.
Answer:
CO2
Explanation:
Diffusion is a simple process of molecular movement, from their higher concentration to the area with their lower concentration. The process of CO2 movement from the pulmonary capillaries into the alveoli is part of the gas exchange (together with oxygen movenent in opposite direction) and it is actually simple diffusion. Alveoli have huge surface area, thin cell walls and a lot of blood vessels around them. All of these are adaptations that facilitate gas exchange. There is a gradient in partial pressure of the CO2: it is much higher in the pulmonary capillaries than in the alveoili so it moves down its gradient-from the blood to the alveoli (exhale).
