Microscope and the Cell Essays - Lenses, Microscopes, Cell Biology

BioLab3 Lab Report 3 Microscope and the Cell Student Name: I.Purpose of the Microscope Define the following terms. Magnificationthe action or process of magnifying something or being magnified, especially visually. Resolving PowerThe ability of a microscope or telescope to distinguish two close together images as being separate. ContrastThe ability to see specimen detail against its background. II.The Compound Microscope EXERCISE 1 Label the parts of the compound microscope 1.Eyepiece2.Arm 3.Course Adjustment4.Fine Adjustment 5.Resolving Nosepiece6.Objectives Lenses 7.Stage Clips8.stage 9.Iris Diaphragm Lever10.Condenser 11.Light Source12.Base Define the following terms. EyepieceContains the Oracular lends which focuses light on the retina of the eye. ArmThe handle for the Microscope. Course Adjustment KnobLarge knob used to make large movements of the objective lens when focusing on specimen. Fine adjustment knobManipulating this knob clarifies detail of the specimen Revolving nosepieceLenses are threaded into the revolving nosepiece. Makes it easier to revolve through lenses. Objective lensesThe simplest optical microscope is the magnifying glass and is good to about ten times (10X) magnification. Stage clipsUsed to secure the slide in position StageThe microscope slide is place here. Iris diaphragm leverRegulate the size of the opening in the diaphragm. Condenserlens that serves to concentrate light from the illumination source that is in turn focused through the object and magnified by the objective lens. Light sourceLocated in the base of the microscope. BaseLowermost part of the microscope on the tab EXERCISE 2 Calculate microscope magnification Calculate the total magnification for each lens combination. Lens Lens Power Ring Color Total Magnification Unaided Eye 1Xnone 1X x 1X = 1X eyepiece10Xnone1X x 10X = 10X Scanning 4Xblack10X x 4x=40x Low Power 10Xgreen10X x 10x=100x High Power 40X yellow10X x 40x=400x Oil Immersion 100X red10X x 100x=1000x III.Viewing Microscope Slides EXERCISE 3 Focusing the microscope Define the following terms. ParcentralProperty of the microscope which keeps the specimen centralized in the field of view from one objective lens to the next. ParfocalThe ability of the microscope to remain in focus when switching from one lens to the next highest. EXERCISE 4 Specimen orientation In which direction does the image move? The image moves to the left. In which direction does the image move? The image moves down. What is the relationship between the movement of the image and the object? The image moves the opposite direction of the object. IV.Microscopic Measurement EXERCISE 5 Measure the diameter of the field of view Calculate the diameter of the field of view of the scanning power (40X) in micrometers (m)? 4,400 micrometers Calculate the size of the diameter of the field of view for each objective lens and record the data. Remember that 1mm = 1000 m. Lens Total MagnificationDiameter mmDiameter m Scanning 40x2.6mm2600um Low Power 100x1.1mm1100um High Power 400x0.3mm300um Oil Immersion1000x.176mm176um EXERCISE 6 Estimate the size of a specimen 1.Estimate the length of the specimen under low power (10X). 1100m 2.Measure the length of the specimen under high power (40X). 4400m What is the relationship between the diameter of the field of view and its power of magnification? It shows what the fraction will be in the circle. A specimen which fills of the field of view under an oil immersion lens (1000X) is how long? 440m A specimen which fills of the field of view under a scanning lens (40X) is how long? 650m A specimen which fills of the field of view under a low power lens (100X) is how long? 257m A specimen which fills of the field of view under a high power lens (400X) is how long? 357m V.Depth of Focus EXERCISE 3.7 Determine depth of focus Determine the order of the colored threads and enter your results below: TopRed MiddleBlue BottomYellow How is the order of the threads determined? the depth and color in the order they are stacked What diaphragm adjustment should be made to more easily determine the order of the colored threads? Push to the left for more detail Explain how depth of focus can be used to reconstruct structure. the better depth the better the detail shows up and causes a better eye to observe VI.Characteristics of Cells Identify the differences between prokaryotic and eukaryotic cells. Characteristics Prokaryotic CellsEukaryotic Cells Genetic materialLocated in nucleoid, a region of cytoplasm not bounded by a membrane. Consists of a single molecule DNA. Located in a nucleus, a membrane bound compartment within the cytoplasm. Made up of DNA molecules of proteins. CytoplasmSmall Ribosomes.Large Ribosomes. VII.Prokaryotic Cells EXERCISE 8 Observe bacteria cells Which magnification is being used to view the bacteria? 400x Can you see cell organelles within the cytoplasm? Yes Measure the approximate size (m) of the bacterial cells. 60m Label the structures of the bacterial cell. 1.Single chromosome 2.Cell Wall 3.Surface membrane 4.Plasmids 5.Cytoplasm VIII.Eukaryotic Cells A.Animal Cells EXERCISE 9 Prepare a wet mount of human cheek cells Estimate the size of a typical cheek