The purpose of lab 1 was to learn about general bacteria’s and the use of a compound microscope. The microscope contains biconvex lenses, bi- meaning two. The basic frame of the micro scope consists of a base, a stage to hold the slide, an arm for easy carrying, and a body tube for transmitting the magnified image. The light source is in the base. One can focus on the image of an object by moving the lens closer to the slide or the stage closer to the objective lens, using the coarse- or fine- adjustment knobs. The two objects that were studied was the Paramecium caudatum which is a bacteria, and Amoeba proteus which is an protozoa. Our hypothesis are that we will discover an bacillus, coccus, or a spiral shaped bacteria.
Paramecium caudatum/ Bacteria
Species of Paramecium can be distinguished from other ciliates by their cigar or slipper shape and the undulating membrane within the peristome - a furrow that leads to the cytostome, where food vacuoles are formed. Most Paramecium are large as protists go, on the order of 0.5 mm long by perhaps 1/3 as wide. Bacteria is a single-celled organism. They are also called prokaryotes. Bactria can take on many shapes but there are three that are more common. Those three shapes are bacillus, which is rod-like; coccus, which is spherical shaped; and spiral. Bacteria has a cell wall that is composed of carbohydrate and protein complex called peptidoglycan. Bacteria can also make their own food by a process called photosynthesis, and some can Page 2
derive nutrition from inorganic substances.
Protozoa are also single celled organism. They are also called eukaryotic chemoheterotrophic organisms. Protozoa inhabit water and soil. They feeds upon bacteria and small particulate nutrients. Protozoa’s have many great uses, they are sold commercially as a nontoxic insecticide to kill grasshoppers but all are not harmful to humans or animals that eat...