Blood is a connective tissue that circulates throughout the body. It is made up of a fluid medium called plasma in which float two types of blood cells, called red blood cells, white blood cells and cell fragments called blood platelets. Blood cells are manufactured in the bone marrow.
These are circular in shape, and contain a red coloured pigment called haemoglobin
No nucleus is present in RBC
RBC carry oxygen to tissues and bring back carbon dioxide from tissues
Since they carry no pigments, they are colourless
They have irregular shape
They prevent body from infections by eating up germs or by producing antibodies to fight antigens
These are very small fragments of cells
They have no nuclei
They participate in clotting of blood
Blood carries nutrients, oxygen, carbon dioxide, hormones and waste material to the relevant parts of the body. Some medicines when taken in the body are also distributed through blood.