Answer:
with each heartbeat,the heart pumps blood throughout our bodies,carrying oxygen to every cell,after delivering oxygen the blood returns to the heart the heart then sends the blood to the lungs to pick up more oxygen.
<span>When plants moved on the land they had to adapt to new environment and </span>to deal with new <span>problems. The main problem for plants was to figure out how to regulate water loss within the cells. One of the solution was the formation of the waxy covering on top of leaves-cuticle, which evolved on the surface of leaves to reduce water loss. Another problem for plants was to figure out how to obtain resources from soil and air, so they developed vascular tissue to transport water/sugar within the plant.</span>
Cnidarians were the first phylum that scientists saw tissue level organization in. Tissue level organization meaning cells all of one type start to function in a unified way.
Each cell is alive even if it is part of a multi celled body, and all living organisms consist of one or more cells. Also, cells reproduce by dividing so it follows that all existing cells must have arisen by division of other cells. As a cell divides it passes it hereditary material- its DNA- to offspring.