Question

Give scientific reasons for the following statements.
(i) Mature erythrocytes within human lack nucleus and mitochondria.
(ii) Blood flows in arteries with spurts and high pressure.

Answer 1

(i) Erythrocytes:

1. The red blood corpuscles (RBCs), also known as erythrocytes are the kind of cells that are present most abundant in the blood.
2. RBCs are red-colored, biconcave, and disc-shaped cells.
3. The reddish color of the RBCs is due to the presence of a respiratory, iron-pigment called hemoglobin.

Mature RBCs:

1. When RBCs mature, they become enucleated.
2. This helps them to carry more hemoglobin for oxygen transport.
3. Also, the erythrocytes lack other cell organelles such as the endoplasmic reticulum and mitochondria.
4. This increases the flexibility of RBCs and prevents cellular respiration in RBCs (using the oxygen by themselves).

(ii)Arteries:

1. Arteries are the blood vessels that carry oxygenated blood from the heart to various organs.
2. The exception is the pulmonary artery which carries deoxygenated blood from the right auricle to the lungs.
3. Arteries are thick-walled.

High pressure:

1. The blood flows in the arteries with spurts and high pressure.
2. This is because the oxygenated blood is meant to reach farther distances from the heart.
3. Also, the high pressure is due to the blood flowing through the arteries after a contraction.