Blood Basics: 16 MCQs with answers

Haemoglobin

Plasma carries nutrients like glucose and amino acids, hormones, and wastes, but haemoglobin is contained in red blood cells, not in plasma.

Erythrocytes

Red blood cells (erythrocytes) are described as disc-shaped (biconcave) and contain haemoglobin.

120 days

The average life span of an RBC is about 120 days, after which they are removed by the spleen and liver.

7000 per mm³

An average of 7000 WBCs per mm³ of blood is present within the normal range for adults.

All of the above

Plasma carries nutrients (glucose, lipids, amino acids), wastes produced by cells, and hormones secreted by endocrine glands.

White blood cells

White blood cells (leukocytes) defend the body against diseases.

It turns bright red in the presence of oxygen and dark red when deoxygenated.

Haemoglobin turns bright red in the presence of oxygen and dark red when deoxygenated.

True

The source states that the average life span of an RBC is about 120 days.

False

WBCs are less in number than RBCs; the average count is 7000 per mm³ compared to millions of RBCs per mm³.

1.5%

About 1.5% of oxygen is dissolved in plasma; the majority is carried by haemoglobin in RBCs.

Red bone marrow of short bones

Before and immediately after birth, RBCs are formed in liver and spleen, but in adults they are formed in the red bone marrow of short bones like sternum, ribs, and vertebrae.

They are colourless and have irregular shapes.

WBCs are colourless, irregular in shape, larger in size, and fewer in number than RBCs. They do not contain haemoglobin.

Liver

Some WBCs mature in lymph nodes, tonsils, thymus, or spleen, but not in the liver. The liver is involved in RBC formation before birth and removal of aged RBCs.

They are broken down.

During the formation of an RBC, its nucleus and organelles are broken down, which allows more space for haemoglobin.

30 trillion

There are more than 30 trillion RBCs throughout the body, while 4-5.5 million is the count per mm³ of blood.

Carrying oxygen

Oxygen is mainly carried by RBCs; plasma carries only a small dissolved amount (about 1.5%). The primary function of plasma is to transport nutrients, wastes, and hormones.