The correct option is (c).
Explanation
Blood is a fluid connective tissue consisting of a fluid matrix, plasma, and formed elements. The formed elements include Erythrocytes (RBCs), Leucocytes (WBCs), and Thrombocytes (Platelets).
Statement-wise Analysis:
- Statement 1 is Correct: Plasma is a straw-coloured, viscous fluid constituting nearly 55 per cent of the blood. It serves as the fluid medium in which the formed elements (RBCs, WBCs, and platelets) are suspended and transported throughout the body.
- Statement 2 is Incorrect: The red colour of blood is due to the presence of an iron-containing complex protein called haemoglobin. In humans, haemoglobin is contained inside the Red Blood Cells (RBCs), rather than being dissolved directly in the plasma.
- Statement 3 is Correct: White Blood Cells (WBCs), also known as Leucocytes, are an integral part of the body's immune system. They are responsible for identifying and destroying pathogens (germs) and protecting the body against infections.
Key Takeaway:
Human blood consists of plasma (fluid) and cells. The red pigment haemoglobin is located within RBCs, not the plasma. WBCs provide immunity.