Multiple choice

The life span of blood platelets in mammals is about

  1. 3 days

  2. 5 days

  3. 10 days

  4. 20 days

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Blood platelets (thrombocytes) have a lifespan of approximately 5-7 days in mammals. Option B at 5 days is the closest. Platelets are much shorter-lived than RBCs (120 days) and don't last 10-20 days.