JBL EMT Practice Exam

What is the function of platelets?

1. Defense against invading organisms

2. Initial formation of a blood clot

3. Transport of cellular waste materials

4. Transport of oxygen and nutrients

The correct answer is: Defense against invading organisms

Platelets, also known as thrombocytes, are small fragments of specialized cells that play a key role in the formation of blood clots to stop bleeding or repair damaged blood vessels. They do this by forming a sticky plug at the site of injury and releasing chemicals that promote blood clotting. Option B is the correct answer because platelets are primarily responsible for the initial formation of a blood clot. Option A is incorrect because defense against invading organisms is the function of white blood cells. Option C is incorrect because the transport of waste materials is the function of red blood cells. Option D is incorrect because the transport of oxygen and nutrients is the function of red blood cells, while platelets do not have this function.