Which of the following correctly describes a normal mature erythrocyte?
a. A 7- to 8-mm biconcave disc that lives 120 days
b. A 7- to 8-mm spheroid that lives 120 days
c. A 12- to 15-mm spheroid that lives 80 days
d. A 12- to 15-mm biconcave disc that lives 80 days
ANS: A
A normal mature red cell has a diameter of 7 to 8 mm, is biconcave, and lives 120 days in circulation.
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