Q.9 - Biology

Question

In humans, the plasma comprises what percentage of the blood? 

a. 45 percent 

b. 55 percent 

c. 25 percent 

d. 90 percent 

Step-by-Step Solution

Answer

The correct answer is (b) 55 percent.

In humans the plasma comprises 55 percent of blood.

Step 1. Introduction

• Blood is actually a term used to describe the liquid that moves through the vessels and includes plasma and the cells (red and white cells) and cell fragments called platelets. 
• Blood plasma is actually the dominant component of blood and contains the water, proteins, electrolytes, lipids, and glucose. The cells are responsible for carrying the gases (red cells) and immune the response (white). The platelets are responsible for blood clotting. 

Step 2. Explanation for the correct answer

(b) 55 percent.

• In humans, cellular components make up approximately 45 percent of the blood and the liquid plasma 55 percent. Blood is 20 percent of a person’s extracellular fluid and eight percent of weight. 
• The liquid component of blood is called plasma, and it is separated by spinning or centrifuging the blood at high rotations. The blood cells and platelets are separated by centrifugal forces to the bottom of a specimen tube.  
• . The plasma also contains the coagulation factors and antibodies. 

Step 3. Explanation for the incorrect answer

a. 45 percent 

• In humans, cellular components make up approximately 45 percent of the blood.
• In humans the plasma comprises 55 percent of blood. Hence this option is not correct.

c. 25 percent 

• In humans the plasma comprises 55 percent of blood. Not 25 percent. Hence this option is not correct.

d. 90 percent 

• In humans the plasma comprises 55 percent of blood. Not 90 percent. Hence this option is not correct.