Depends on the type of blood cell you're talking about.
Platelets are the "cells" that are responsible for forming a clot when you but yourself, whereas whiteblood cells are responsible for fighting any infection that may come in through the cut. Red blood cells are responsbile for carrying oxygen, and don't do anything in the context of a cut. They just leak ;-)
The job of red blood cells is to carry oxygen.
No, that is the job of the various white blood cells.
your body needs red blood cells to survive, red blood cells have a particular job, they Carry oxygen through your bloodstream to all your muscles and flesh. your muscles and flesh need oxygen to work properly (this is why when you cross your legs, sometimes your legs feel funny) they also make your blood look red, which doesn't help you at all, but wouldn't you look weird if whenever you got a cut you bled clear? :)
To carry oxygen
The blood's most important job is the movement of wastes, oxygen, and nutrients to and from body cells. This movement allows the cells to maintain cellular homeostasis.
Your blood. Iron is essential for your blood cells to do their job.
kill
They're specialised because their sole job is to transport oxygen to the body's cells, and carry carbon dioxide away. This is similar to white blood cells who's only job is to defend the body from invading diseases.
The job of a blood cell is to pick up oxygen from the lungs and carrying oxygen to the other cells in the body.
Plasma is a part of blood that is yellowish in color. Its job is to hold the blood cells in suspension.
They transport oxygen around the body.
Spleen!