Somatic Cells

Any biological cell that constitutes the body of an organism is referred to as a somatic cell. Somatic cells include all body cells except germ cells (gametes) and embryonic stem cells. Certain adult stem cells, such as hematopoietic stem cells, are considered somatic stem cells.

Somatic cells undergo mitotic division to form and sustain the structural and functional components of the body of an organism. Somatic cells might pass on DNA mutations to their cellular descendants that can affect an individual, but not to the offspring of that individual.

In humans, somatic cells are diploid, containing two sets of chromosomes (46 chromosomes), one inherited from each parent.

Somatic Cells Characteristics

These cells constitute the majority of the cellular makeup of the body, maintaining the overall function. Important characteristics of somatic cells in eukaryotes are as follows-

Mostly diploid, containing two sets of chromosomes, inherited one from each parent. While diploidy preserves genetic stability in the individual, genetic diversity primarily results from recombination during gamete formation, not from somatic cell division.
Specialised to execute specific functions within the body.
Do not partake in gamete formation, unlike the germ cells, and thus, have no role in reproduction.
Undergo mitosis to yield two identical daughter cells. Mitosis is vital for tissue growth, repair, and replenishment.
Have a finite lifespan and eventually undergo apoptosis (programmed cell death).
Can selectively express necessary genes for specific functions; this enables the cells to perform distinct roles despite having the same genetic makeup.
In an individual, genetically identical somatic cells can accumulate mutations over time; unregulated mutations can also lead to cancer.

Somatic Cells In Plants

In plants, the somatic cells or vegetative cells are fundamental units of the structure of a plant, excluding the reproductive cells. They perform several essential functions-

Contribute to the growth and development of the plant.
Facilitate photosynthesis in chloroplast-containing green regions of a plant.
Provide structural support to the plant.
Store nutrients and water and help in their transport throughout the plant.

Somatic Cells In Animals

In the human body, there are over 200 types of somatic cells, each performing specific functions. Some of the specialised somatic cells are-

Skin Cells have a unique regeneration quality.
Nerve Cells (Neurons) receive and propagate signals throughout the body; thus, they are responsible for the control and coordination of bodily functions.
Muscle Cells (Myocytes) are again specialised cells to

Smooth muscle cells are present in the internal lining of visceral organs, the digestive tract, and the urinary tract.
Cardiac muscle cells present in the heart help in the pumping of blood.
Skeletal muscle cells are attached to bones that help in movement

Blood Cells are also differentiated into
Erythrocytes or Red blood cells (RBCs) transport oxygen from the lungs to tissues and carry carbon dioxide back to the lungs for exhalation.
Leucocytes or White blood cells (WBCs) protect against foreign antigens and infections.
Platelets or Thrombocytes are responsible for the clotting of blood.

Frequently Asked Questions (FAQs)

Q1. Why are stem cells not considered somatic cells?

A. Both stem cells and somatic cells are diploid and multiply their number through the equational mitotic division. While somatic cells constitute the cellular makeup of an individual, stem cells are unspecialised with a unique self-renewal capacity. Stem cells can endlessly replenish other cell types of multicellular organisms.

Q2. Is sperm a somatic cell or a germ cell?

A. Sperm is not a somatic cell. It is rather a gamete which is derived from germ cells (spermatogonia) through meiosis. In males, sperm are the haploid gametes produced due to the meiosis of the diploid germ cell spermatogonia.