Cilia are slender, microscopic, hair-like structures or organelles that extend from the surface of nearly all mammalian cells (multiple or single).ource: Amelia Shoemark. ' Motile ' (or moving) cilia are found in the lungs, respiratory tract and middle ear. These cilia have a rhythmic waving or beating motion (see right). They work, for instance, to keep the airways clear of mucus and dirt, allowing us to breathe easily and without irritation.
Share. The visible light spectrum is the section of the electromagnetic radiation spectrum that is visible to the human eye. It ranges in wavelength from approximately 400 nm (4 x 10 -7 m) to 700 nm (7 x 10 -7 m). It is also known as the optical spectrum of light. By Andrew Zimmerman Jones.
The visible spectrum is a subset of the electromagnetic spectrum that is visible to the human eye. The wavelength range from about 390 to 750nm and frequency, 400â790Hz is the part of visible spectrum.In other words, visible spectrum lies between the frequencies of the ultraviolet rays and infrared waves. It is only this part which our eyes can see. 2  Visible light is produced from stars, arc lamps and glass enclosed tungsten filaments. 3  It lies in a narrow range of wavelength between 300nm to 760nm. 4  It lies between the Ultra-violet radiation and Infra red radiation of the electromagnetic radiation [EMR].