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.
Light is a form of electromagnetic radiation. Visible light is a narrow range of wavelengths of the electromagnetic spectrum. By measuring the wavelength or frequency of light coming from objects in the universe, we can learn something about their nature. Since we are not able to travel to a star or take samples from a galaxy, we must depend on electromagnetic radiation to carry information to us from distant objects in space. The human eye is sensitive to a very small range of wavelengths called visible light.