What percentage do plasma and formed elements together account for in whole blood?

What percentage do plasma and formed elements together account for in whole blood?

• A. 100%
• B. 90%
• C. 110%
• D. 95%

Answer: (A)

The key idea is that whole blood is made up of two components—plasma and formed elements—that together constitute the entire blood volume. Plasma is the liquid portion (about 55%), and formed elements (red blood cells, white blood cells, and platelets) make up the remaining about 45%. When combined, they account for 100% of whole blood. That’s why the correct answer is 100%. The other options don’t fit because they would imply a portion of blood is not accounted for by these two components, which isn’t the case.

The key idea is that whole blood is made up of two components—plasma and formed elements—that together constitute the entire blood volume. Plasma is the liquid portion (about 55%), and formed elements (red blood cells, white blood cells, and platelets) make up the remaining about 45%. When combined, they account for 100% of whole blood. That’s why the correct answer is 100%. The other options don’t fit because they would imply a portion of blood is not accounted for by these two components, which isn’t the case.