Concise Selina Solutions for Class 9 Biology Chapter 13 Skin The Jack of all Trades

The skin is the largest organ of the body, with a total area of about 2 square metres. The skin protects us from microbes and the elements, helps regulate body temperature and permits the sensations of touch, heat and cold. Skin is called the jack of all trade because the skin is our body's primary organ from which significant body functions such as sweating. Through sweat pores from our skin eliminate urea and excess salts such as NaCl from our body and many other functions. Skin is a complicated organ that performs many tasks in the body and is therefore sometimes properly called "The Jack of all trades," meaning it performs various tasks but is "master of none." The primary function of the skin is to act as a barrier. The skin protects from mechanical impacts and pressure, variations in temperature, micro-organisms, radiation and chemicals.