Question

Ratio of WBC to RBC in human blood is:
A. 1:100
B. 1:200
C. 500:1
D. 1:600

Answer 1

Hint: The number of RBC is enormous compared to WBC, as blood is required to supply oxygen and nutrients to every tissue in our body.

Complete answer:
A healthy human being contains about 5-5.5 million red blood cells per $mm^3$ of blood on average. The number of RBCs is a bit higher in males than females; this is because of the presence of testosterone in males. The number of leucocytes of WBC is around 4000-11000 per $mm^3$ of blood. So the ratio of WBC to RBC comes up to be 1:600.

Additional Information:
Properties of RBCs or red blood cells are as follows:
- All red blood cells in an adult mammal are non-nucleated and no cell organelles are present.
- Biconcave in shape.
- An unusual rise in the number of RBCs is called polycythemia and a decrease in the total number of RBCs is known as erythrocytopenia.
 - They are also known as erythrocytes.
- The process of formation of erythrocytes is known as erythropoiesis.

Properties of WBCs or white blood cells are:
- They are also known as leukocytes.
- Leukocytes are of two types, granulocytes and agranulocytes. The granulocytes have the presence of granules in their cytoplasm and usually have a multilobed nucleus.
- Granulocytes include eosinophils, basophils, and neutrophils.
- Agranulocytes lack visible granules in their cytoplasm. They are of two types, lymphocytes, and monocytes.

So, the correct answer is, “ Ratio of WBC to RBC in human blood is 1:600.”

Note: It is important to know that both agranulocytes and granulocytes have granules in their cytoplasm, but the granules in the cytoplasm of agranulocytes are not visible under a compound microscope. RBCs are responsible for supplying nutrients and oxygen to every cell of our body, whereas WBCs are related to the immunity of our body. RBCs are non-nucleated in most adult mammals, except in camel and llama.