Question

The size of Red Blood Cells (RBCs) is around:
A) $$1000$$nm
B) $$2000$$nm
C) $$5000$$nm
D) $$9000$$nm

Answer 1

Hint: First we have to know that blood is made up of liquid and solids. The liquid part is called plasma, it is made of water, salts, and protein. Over half of your blood is plasma. The solid part of your blood contains red blood cells, white blood cells, and platelets. An MCV (Mean Corpuscular Volume) blood test measures the average size of red blood cells is also known as erythrocytes.

Complete answer:
Red blood cells, also referred to as red cells, red blood corpuscles, haematids, erythroid cells or erythrocytes. Hemoglobin is the protein inside red blood cells. It carries oxygen. Red blood cells also remove carbon dioxide from your body, bringing it to the lungs for you to exhale. Red blood cells are made in the bone marrow. They typically live for about 120 days, and then they die.

The size of normal Red Blood Cells is around $$6$$ to $$8$$microns (micrometres) in diameter.
i.e. ($$6$$to $$8$$) $$\times {10}^{-6}$$ m.
which is also written as ($$6000$$ to $$8000$$)$$\times {10}^{-9}$$ m
Since we know that $$1$$ nanometre $$={10}^{-9}$$m
Hence red blood cells is around ($$6000$$ to $$8000$$nm
So, out of four options, the option C. $$5000$$nm lies near this range.

Additional information: White blood cells are bigger than red blood cells. When a person has a bacterial infection, the number of white cells can increase dramatically to protect you against then.

Hence the correct option is C. $$5000$$ nm.

Note: Note that students can’t answer this question if they don’t know that $$1$$ nanometre $$={10}^{-9}$$m and $$1$$ microns$$={10}^{-6}$$m. Also note that when comparing options, we have to take the nearest size which is less than the exact size. Red blood cells carry oxygen from our lungs to the rest of our bodies. Then they make the return trip, taking carbon dioxide back to our lungs to be exhaled.