Hint: Blood is a form of fluid connective tissue. It comprises blood cells i.e. RBC and WBC, plasma, and platelets. It flows throughout our body and circulates blood and oxygen to all the parts of the body. In an adult, almost 5-6 litres of blood is present.
Complete answer: After the clotting of blood, the straw-colored fluid that's left is called plasma. It makes up about 60% of blood. It contains some proteins and dissolved substances. Apart from water it also contains clotting factors and fibrinogen. It also contains lipids, glucose and salts. It can be separated from blood with the help of anticoagulants. It can also be stored in a frozen condition for up to a year. The main protein present in plasma is albumin which also helps to detect osmotic pressure.
The blood supplies oxygen to the whole body and also plays a vital role in the removal of carbon dioxide and other waste products from the tissues. It also helps in the circulation of white blood cells for immunological functions. It also helps in clotting at the injury site and helps to maintain the temperature and pH of the body. While plasma, on the other hand, maintains electrolytes and fluids in the body and serves as a protein reserve for the body. It helps in the transfer of essential nutrients, hormones, waste, and other substances to and from the tissues.
Note: The blood plasma can be separated by a device called centrifuge by spinning the blood in it till all the cells settle at the bottom of the tube. Red blood cells have a very important role of carrying oxygen to all the parts of the body. They also contain hemoglobin. Hemoglobin contains iron which when combined with oxygen gives hemoglobin and our blood, a red color.