The correct answer is (a) 1, 2 and 3.
Haemoglobin is a protein found in red blood cells that carries oxygen from the lungs to the rest of the body. It is an iron-containing compound, and it is this iron that gives blood its red color. Haemoglobin also plays a role in the immune system, but it does not provide immunity against certain diseases.
Statement 1: Haemoglobin carries oxygen in the blood. This is true. Haemoglobin is a protein found in red blood cells that carries oxygen from the lungs to the rest of the body.
Statement 2: Haemoglobin is an iron containing compound. This is true. Haemoglobin contains iron, and it is this iron that gives blood its red color.
Statement 3: Haemoglobin provides immunity against certain diseases. This is false. Haemoglobin does not provide immunity against certain diseases.
Statement 4: Haemoglobin imparts red color to the blood. This is true. Haemoglobin contains iron, and it is this iron that gives blood its red color.