Question

The smallest human cell is :
A. Erythrocyte
B. Kidney cell
C. Liver cell
D. Sperm

Answer 1

Hint: A cell is described as the smallest, basic, and functional unit of life in charge of all the processes of life. A cell is composed of plasma membrane and cellular organelles.

Complete Answer:
Option a) : Erythrocyte (RBC) - It is a type of blood cell (formed in the bone marrow). It contains a protein called hemoglobin. A human RBC is approximately 7.5-8.7 micrometer in diameter and 1.7-2.2 micrometer in thickness.
This option is incorrect.

Option b) : Kidney cell - Kidneys filter toxins out, remove the wastes and extra fluid, control blood pressure. A half of 1 kidney can do the job performed by both the kidneys together. Podocytes are cells in the Bowman's capsule in the kidneys, and measure around 20 microns in size.
This option is incorrect.

Option c) : Liver cell - Hepatocytes are approximately 80% of the cells in the liver. A typical hepatocyte is cubical with sides of 20-30 micrometer, (if compared - a human hair is of the diameter 17-180 micrometer).
This option is incorrect.

Option d) : Sperm - A human sperm cell consists of a flat, disc shaped head 5.1 µm x 3.1 µm and a tail 50 µm long. The tail whips in an elliptical cone, to propel the sperm cell (at the rate of about 1–3 mm/minute).
Many researchers consider the Sperm cell to be the smallest cell in the human body.
Thus, this is the Correct option.

Thus, their correct option is D) sperm.

Note: According to many others, the Granule Cell of the Cerebellum is the smallest cell in the human body (4 micrometers - 4.5 micrometers long). The largest cell is ovum (egg cell) in the human body (diameter of about 0.1 mm). It is 20 times bigger than the sperm cells.