1 DNA is a polymer. 2  Individual monomer units are called nucleotides. 3  The DNA polymer is composed of: 4  a backbone of molecules of the sugar deoxyribose (a 5 carbon sugar). 5  phosphate groups linking the deoxyribose sugar molecules together in a chain. The DNA polymer is composed of: 2  a backbone of molecules of the sugar deoxyribose (a 5 carbon sugar). 3  phosphate groups linking the deoxyribose sugar molecules together in a chain. 4  four principal bases (2 are pyrimidines and 2 are purines):
Rods and cones function as photoreceptors in the retina of the eye, turning visible light into neuronal signals, which are sent to the brain. This process is called transduction. Rods and cones perform at different wavelengths and sensitivities allowing detailed perception of light and color.
Loss Rod Cells can result in the condition known as Night Blindness. <b>Rods r</b><b>espond to very low levels of light and are primarily responsible for night vision.</b><br /> They also: <br /> A Rod Cell is a type of light-sensitive nerve cell found in the retina. Rod cells do not process fine details or colour differences but are highly sensitive to light. A single photon of light is all that is require to produce a response from a Rod Cell. Loss Rod Cells can result in the condition known as Night Blindness.