Human evolution known to be a process in which species adapt to certain conditions of life, and in the battle of life and death, they are forced to become stronger in order to survive in the world. Diseases have always been present during the evolution, acting themselves as a natural selector-the weaker organisms get sick and die.
Circulatory system;<span>The circulatory </span>system<span> circulates blood through the </span>body<span>, </span>supplies<span> cells with </span>oxygen<span> and </span>nutrients<span> and</span>removes waste<span> products. Organs: heart, arteries, veins. ... The respiratory </span>system supplies<span> blood with
</span>oxygen<span> in the lungs and </span>removes<span> carbon dioxide.</span>
B .How organisms could change .
Tubes for Transporting Food-carrying tubes Phloem Water-carrying tubes Xylem Sugar is produced In the leaves. The food-carrying tubes transport this sugar from the leaves to the other parts of the plant. The root hairs found on the roots Take in water and mineral salts from the soil.