Question

Red blood cell as a life span of 100-120 days. after its death its goes out from our body or what happens to it..?

Answer 1

After the death of red blood corpuscles are transferred to spleen which is also known as graveyard of RBC and the dead RBCs get degenerated.

Hope it helps.

Answer 2

hii friend!
A tripling of red blood cell (RBC) lifespan would probably not result in any substantial or significant change. These RBSs have no nuclear DNA, so if damaged or mutated, they still would not pass along the anomalies to future cells.  These cells die because they essentially "wear out" through constant circulation around the body through the smallest of passages. They break open, they tear, and they get stuck or damaged. Increasing their lifespan would require toughening them up--perhaps alterations to the cell's membrane.

hope this helps ^_^