Understanding Blood and Its Components

Blood is essential for transporting substances throughout the body. Red blood cells, formed in the bone marrow, carry oxygen to tissues and remove carbon dioxide. Blood is composed of cellular elements and plasma, with red blood cells making up 45% of its volume. The formation of red blood cells involves stem cells and takes about two days, with the body producing millions every second. Blood can be separated into its components using a centrifuge.

What is the primary function of red blood cells in the body?

• To digest food

• To produce hormones

• To fight infections

• To transport oxygen

Where are red blood cells formed in the body?

• In the heart

• In the kidneys

• In the liver

• In the red bone marrow

What is the name of the cell that develops into a new red blood cell?

• Lymphoblast

• Megakaryoblast

• Proerythroblast

• Myeloblast

Approximately how many red blood cells does the body produce every second?

• 5 million

• 10 million

• 1 million

• 2 million

What percentage of blood is made up of plasma?

• 75%

• 55%

• 45%

• 65%

Which component of blood is less than 1% of its composition?

• Red blood cells

• White blood cells and platelets

• Hemoglobin

• Plasma