What is the role of haemoglobin in the blood?

In which organ of our body does blood become oxygenated?

Name the disease in which the number of platelets reduces to 25,000 - 30,000 per cu mm of blood. State its major symptoms.

Name the following :

1. Three components of circulatory system
2. Three kinds of blood vessels
3. Three kinds of corpuscles
4. Two types of blood circulation in human body
5. Four categories of blood groups on the basis of the proteins found on the surface of RBCs.