Somatic Cells

Somatic Cells

Somatic cells account for all the cells of the body except reproductive cells. Other than gametes, stem cells and germs cells, all the cells of a multicellular organism are known as somatic cells.

Diploid somatic cells undergo mitosis and are responsible for growth, repair and regeneration.

Somatic terms originate from the word ‘Soma’, which means ‘body’. They make up the entire organism other than cells, which have a reproductive function or are undifferentiated, e.g. stem cells.

🔹Somatic Cells Characteristics

➖Somatic cells are responsible for the growth and development of an organism

➖They are required for repair and regeneration

➖Somatic cells undergo mitosis and contain the same set of chromosomes as the organism

➖Somatic cells have a diploid set of chromosomes as compared to gametes, which are produced by meiosis (reduction division) and have a haploid set of chromosomes

➖Many species like wheat have a varied set of chromosomes in their somatic cells, e.g. hexaploid, triploid, tetraploid, etc.

➖Somatic cells undergo mutation more frequently as compared to germ cells

➖Somatic cells are used for cloning by which identical clone of an individual is produced

➖“Somatic cell nuclear transfer” is one such process where the nucleus of a somatic cell is transferred to an ovum cell. It is then implanted into the uterus and we get the identical clone. “Dolly the sheep” was cloned from an adult somatic cell

➖Somatic cells are used to conserve genetic information of animals

➖Genetic engineering and manipulation of somatic cells is controversial but of great importance to research and biotechnology

🔹Somatic Cells Types and Examples

There are numerous types of somatic cells. In our body, there are 220 types of somatic cells. Many cells are differentiated to perform various specific functions.

Some of the specialised somatic cells are:

➖Skin Cells: They have a unique quality of regeneration.

➖Nerve Cells: Neurons are specialised cells, which receive and propagate signals to and from the brain and spinal cord to other parts of the body. They are responsible for the control and coordination of bodily functions.

➖Muscle Cells: Myocytes are specialised cells to perform different functions. There are three main types of muscles:

       Smooth muscle – Internal lining of internal organs, digestive tract and urinary tract

       Cardiac muscle – Present in heart and helps in the pumping of blood

       Skeletal muscle – Attached to bones and helps in body movement

➖Blood Cells: Blood is composed of many differentiated cells:

         Erythrocytes – Red blood cells (RBCs) carry oxygen to different tissues. In humans, RBCs are biconcave and anucleated

         Leucocytes – White blood cells (WBCs) provide protection against foreign antigens and infections. There are five main types of WBCs

         Platelets – Thrombocytes are responsible for blood clotting