Question

The normal red cell lasts approximately ______ before it is destroyed.

(a) 90 days

(b) 210 days

(c) 120 days

(d) 60 days

The question was posed to me in a job interview.

Origin of the question is Intravascular Oximeters in division Oximeters of Biomedical Instrumentation

Answer 1

Right answer is (c) 120 days

The explanation is: In the whole body, there are about 25 billion erythrocytes and they are constantly being destroyed and replaced at a rate of about 9000 million per hour. The normal red cell lasts approximately 120 days before it is destroyed.