In multicellular organisms, life begins as a single cell until occurs, causing growth.

In multicellular organisms, life begins as a single cell until cell division (e.g. mitosis and meiosis) occurs, causing growth. When cells divide they form identical daughter cells that sprung from a parent cell. This happens when repair to damage tissues occur within the body of organisms. Cells multiply in numbers to cause growth in tissues and organ systems in different organisms. Without cell division, repairs and major growth in species through DNA coding will not occur.

It depends on the surface of the levels. the rougher the surface, the greater is the frictional force. for rougher surfaces, you would need to exert greater force to move the object. the concept is that, you must overcome the frictional force in order to bring the object into motion. this is the reason why we add lubricants to the joints so they could easily move. this answer was on