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.
Vacuole Function. The Vacuole is a cell organelle that is present only in plant cells. The main vacuole Function is in maintaining the structure and shape of the cell. Cells of plants do not increase in size by expanding their cytoplasm but by increasing the size of their vacuoles.acuole Function. The Vacuole is a cell organelle that is present only in plant cells. The main vacuole Function is in maintaining the structure and shape of the cell. Cells of plants do not increase in size by expanding their cytoplasm but by increasing the size of their vacuoles.