1. Label and describe the function of each of the following parts of the microscope (7)
A. The ocular lens/eyepiece transmits and magnifies the image from the objective lens to the eye.
B. The body tube transmits the image from the objective lens to the ocular lens.
C. The nosepiece is a rotating mount holding many objective lenses.
D. The objective lens is the primary lens that gathers as much light as possible from the specimen and brings it to a bright focus.
E. The stage is where the specimen rests.
F. The condenser focuses light through the specimen.
G. The illuminator/lamp is the microscope’s light source.
H. The coarse-focus knob brings the object into the focal plane of the objective lens.
I. The fine-focus knob makes fine adjustments to focus the image.
J. This is the arm of the microscope.
K. The clips hold the specimen still on the stage.
L. I think this could be another coarse-focus knob.
M. This is the base of the microscope
2. What is the function of immersion oil? How does it work? (2)
Oil immersion is a technique used to increase the resolution of a microscope. It works because of the oil’s refractive properties. The oil works as a sort of secondary lens, magnifying the specimen in addition to the lens already present.
3. Describe the differences you observed between the cells seen on the blood slide and those seen on the bacterial slides. (1)
They were very much so different. The yogurt cells were rod-like and fairly widely distributed. The blood cells on the other hand, were round and appeared in one giant cluster tightly packed together.
4. What is the difference between direct and indirect staining? (1)
Direct staining stained bacteria with basic dye (methylene blue, carbol fuchsin, crystal violet, etc) which its coloring power is in positive ion, and reacts with the negatively charged cell. Thus, the bacterial cell will be stained with the basic dye's color. In other words, direct staining