Answer:
Arteries carry oxygenated blood away from the heart. Veins carry the blood back to the heart. Veins contain valves that ensure blood flows in only one direction. Arteries don’t require valves because pressure from the heart is so strong that blood is only able to flow in one direction.
Explanation:
Answer: C.
because I translated it to what the answer is
<span>The answer is a certain required chemicals must be actively
transported. Blood brain barrier is a
selective membrane that separates blood circulating from the brain and the
fluid of extracellular in the central nervous system. This is also called a
filtering mechanism, the capillaries that carry blood to the brain and spinal
cord tissue blocking the path way of the certain substance.</span>
This means that the mothers green eyes are recessive alleles and the fathers brown eyes are dominant alleles. The blue eyed puppy is blue eyed because there must have been a gene in the mothers or fathers past generation.
<span>Three months after fertilization and development of a placenta around the developing fetus, the corpus luteum regresses and forms the corpus albicans.</span> Formed placenta takes over progesterone production (which was the role of corpus luteum) and the corpus luteum degrades into a corpus albicans. The corpus luteum is being broken down by macrophages, in a process called luteolysis. The remains of the corpus albicans may persist as a scar on the ovary.
