Which statement best describes plasma relative to clotting in blood samples?

Which statement best describes plasma relative to clotting in blood samples?

• A. Plasma is the liquid portion of unclotted blood and contains clotting factors
• B. Plasma is the liquid portion of clotted blood
• C. Plasma lacks clotting factors
• D. Plasma is the solid component

Answer: (A)

The key idea is distinguishing plasma from serum and how clotting status changes what you see. Plasma is the liquid portion of blood that has not clotted yet; when blood is collected with an anticoagulant and then centrifuged, the liquid supernatant you obtain is plasma, and it still contains clotting factors such as fibrinogen. If the blood is allowed to clot, the solid clot forms and the liquid that remains after removing the clot is serum, which lacks most clotting factors because they were consumed in the clotting process. Therefore, saying plasma is the liquid portion of unclotted blood and contains clotting factors is correct. The other options misidentify plasma as coming from clotted blood, claim it lacks clotting factors, or describe it as the solid component.

The key idea is distinguishing plasma from serum and how clotting status changes what you see. Plasma is the liquid portion of blood that has not clotted yet; when blood is collected with an anticoagulant and then centrifuged, the liquid supernatant you obtain is plasma, and it still contains clotting factors such as fibrinogen. If the blood is allowed to clot, the solid clot forms and the liquid that remains after removing the clot is serum, which lacks most clotting factors because they were consumed in the clotting process. Therefore, saying plasma is the liquid portion of unclotted blood and contains clotting factors is correct. The other options misidentify plasma as coming from clotted blood, claim it lacks clotting factors, or describe it as the solid component.