Arteries take blood from the heart. the walls of an artery are made up of thick walls and elastic fibres. veins carry blood the heart and also have valves. the link arteries and veins, and have a one cell thick wall. blood is made up of four main things the liquid part of the blood; red blood cells to carry ; white blood cells to protect the body from disease and to blood clot.

Put each tile to the correct location. categorize each term as something that is typical of a scientific theory, a scientific hypothesis, or both. 1) scientific theories 2) both 3) scientific hypothesis a). a tentative statement used to guide scientific investigations b). makes predictions about future events c). can be tested many independent researches d). based on observations of natural phenomena e) . a well-established highly reliable explanation