Biology: The Study of Life
Blood: pages 162 – 166
Questions: page 176, section questions: # 1 – 7
1. Name the cells of formed elements of blood.
The three formed elements of blood are: red blood cells, white blood cells and
platelets.
2. Which blood cell is most abundant?
Red blood cells are the most abundant blood cell in the human body.
3. What is the type of leukocyte that engulfs microorganisms?
White blood cells are leukocytes. There are two types of leukocytes. The type of
leukocyte that engulfs microorganisms is called a phagocyte.
4. What is the function of platelets?
Platelets trigger the blood clotting process.
5. What is the insoluble protein that traps blood cells to form a clot?
Fibrin is the insoluble protein that acts to trap red blood cells and platelets to fill a
wound.
6. List three conditions that cause blood not to clot normally.
a. Hemophilia – condition where one of the clotting factors is missing from
the blood
b. Deficiency of platelets in the blood
c. Vitamin K deficiency (vitamin K is needed to make prothrombin, a protein
that is necessary for fibrin to eventually be formed)
7. What prevents blood from clotting within the blood vessels?
There are two factors that prevent this from happening:
a. The structure of the inner wall of the blood vessels prevents clotting from
being activated
b. Our blood contains anticoagulants (a chemical that prevents clot
formation)