A red blood cell is a biconcave disc packed with the red pigment haemoglobin. Red blood cells are responsible for carrying oxygen from the lungs to the tissues where it is needed for respiration. Red cells have no nucleus and they live for about 120 days, before being destroyed.
White blood cells are much more varied - there are several different types and they form a major part of the immune system of the body. This system defends the body against disease, such as that caused by infection by viruses or bacteria or fungi or parasites. White cells all have nuclei and a very long lived, lasting for years in the body.
The immune system also helps to kill off cancer cells very early in their development - without this function, cancer would be a lot more common.
White cells called B cells produce anitbodies and white cells called T cells attack bacteria, viruses and parasites directly and also kill infected body cells to limit the infection.
White blood cells are much more varied - there are several different types and they form a major part of the immune system of the body. This system defends the body against disease, such as that caused by infection by viruses or bacteria or fungi or parasites. White cells all have nuclei and a very long lived, lasting for years in the body.
The immune system also helps to kill off cancer cells very early in their development - without this function, cancer would be a lot more common.
White cells called B cells produce anitbodies and white cells called T cells attack bacteria, viruses and parasites directly and also kill infected body cells to limit the infection.
