Doublet
(Science: microscopy) two simple lens elements cemented together, for the purpose of giving spherical and chromatic corrections. An achromatic doublet may be composed of a positive crown-glass lens and a negative flint-glass lens. The errors of one element are made to compensate those of the other element.
This lesson is about the methods used for ecological research, such as quadrat and transect sampling, canopy fogging, an..
DNA is a double helix structure comprised of nucleotides. A nucleotide, in turn, is made up of phosphate molecule, deoxy..
Bryophytes (nonvascular plants) are a plant group characterized by lacking vascular tissues. They include the mosses, th..
This tutorial elaborates on how the nervous system works, particularly at the tissue level of the brain. There are three..
Illusions are the perceptions and sensory data obtained from situations in which human error prevents us from seeing the..
This tutorial describes the sigmoid curve, annual plant growth, tree growth, human growth, and insect growth as the grow..
