An assemblage of different types of populations living in the same habitat is called a community. Eg, microbes grow in their habitat, deplete nutrients required for growth and excrete wastes, thus changing the environment they live in. Laboratory Studies Of Microbes Knowledge on microbial structures, physiology, biochemistry and genetics can be better understood from homogenous populations rather than form mixed populations. Homogenous populations can be obtained in the laboratory by using microbiological procedures. A. Microscopes and Microscopy Techniques Microscopes magnify cells too small to see by naked eyes.
Resolution is the degree of detail that is retained in the magnified image.
Oil immersion lenses has short focal length ie the plane of focus is near the lens and therefore there is a short working distance between the objective lens and the specimen. Short working distance results in a very shallow depth of field , ie only a very thin section of the specimen cen be in focuss at any one time. Oil immersion lens also have an RI in common with glass rather than air which improves resolving power. Eucaryotes have enought contrasting structures and can be viewed without staining ie live cells observed. Dyes are organic compounds that have affinity for specific cellular material and increase contrast.