The right answer is vein (it contains blood and has valves).
The infra-cardiac veins of small and medium caliber possess this system of fight against gravity. The valves consist of a dense connective tissue, surmounted by endothelial cells, corresponding to a fold of the intima. They allow blood circulation in the sense organ / heart but prevent venous reflux.
Answer:
Cell theory meets the definition of a scientific theory because it can be proven, it has been tested for a long period of time and therefore there are many evidences that support the theory but not enough to become a law. Well scientific laws are statements based on repeated experiments or observation, but also, a law is something that always applies under the same conditions. Evolution occurs in the characteristics of living things within a species overtime. . A theory is much more complex: it explains why something happens. A law only describes what happens.
The cell theory meets the definition of a scientific theory but i do not think it should be a scientific law.
Explanation:
Answer:
glucose
Explanation:
cell membrane most easily?
Answer: Rosalind Franklin
Explanation: Rosalind was the first oerson to get a picture while Watson and Crick came up with the strusture and won the nobel piece prize