Textbook Question
Why is a mordant used in the Gram stain? In the flagella stain?
Ch. 3 - Observing Microorganisms Through a Microscope
Tortora14th EditionMicrobiology: An IntroductionISBN: 9780138200398
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Table of contents
- Ch. 1 - The Microbial World and You18
- Ch. 2 - Chemical Principles20
- Ch. 3 - Observing Microorganisms Through a Microscope18
- Ch. 4 - Functional Anatomy of Prokaryotic and Eukaryotic Cells21
- Ch. 5 - Microbial Metabolism20
- Ch. 6 - Microbial Growth20
- Ch. 7 - The Control of Microbial Growth20
- Ch. 8 - Microbial Genetics19
- Ch. 9 - Biotechnology & DNA Technology20
- Ch. 10 - Classification of Microorganisms15
- Ch. 11 - The Prokaryotes: Domains Bacteria and Archaea14
- Ch. 12 - The Eukaryotes: Fungi, Algae, Protozoa, and Helminths17
- Ch. 13 - Viruses, Viroids, and Prions20
- Ch. 14 - Principles of Disease and Epidemiology21
- Ch. 15 - Microbial Mechanisms of Pathogenicity19
- Ch. 16 - Innate Immunity: Nonspecific Defenses of the Host20
- Ch. 17 - Adaptive Immunity: Specific Defenses of the Host20
- Ch. 18 - Practical Applications of Immunology20
- Ch. 19 - Disorders Associated with the Immune System19
- Ch. 20 - Antimicrobial Drugs19
- Ch. 21 - Microbial Diseases of the Skin and Eyes21
- Ch. 22 - Microbial Diseases of the Nervous System19
- Ch. 23 - Microbial Diseases of the Cardiovascular and Lymphatic Systems20
- Ch. 24 - Microbial Diseases of the Respiratory System20
- Ch. 25 - Microbial Diseases of the Digestive System20
- Ch. 26 - Microbial Diseases of the Urinary and Reproductive Systems19
- Ch. 27 - Environmental Microbiology20
- Ch. 28 - Applied and Industrial Microbiology19
Tortora14th EditionMicrobiology: An IntroductionISBN: 9780138200398Not the one you use?Change textbook
Chapter 3, Problem 4
Calculate the total magnification of the nucleus of a cell being observed through a compound light microscope with a 10x ocular lens and an oil immersion lens.
Verified step by step guidance1
Identify the magnification of the ocular lens (eyepiece), which is given as 10x in the problem.
Determine the magnification of the objective lens. Since the problem states an oil immersion lens, this typically has a magnification of 100x.
Recall that the total magnification of a compound light microscope is calculated by multiplying the magnification of the ocular lens by the magnification of the objective lens.
Write the formula for total magnification as: \(\text{Total Magnification} = \text{Ocular Magnification} \times \text{Objective Magnification}\).
Substitute the known values into the formula: \(\text{Total Magnification} = 10x \times 100x\) and then multiply to find the total magnification.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Total Magnification in Microscopy
Total magnification is the product of the magnification powers of the ocular (eyepiece) lens and the objective lens. It determines how much larger the specimen appears compared to its actual size. For example, a 10x ocular lens combined with a 100x objective lens results in 1000x total magnification.
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06:15
Components & Magnification of the Compound Light Microscope
Ocular Lens (Eyepiece)
The ocular lens is the lens closest to the observer's eye in a compound microscope, typically providing a fixed magnification, often 10x. It further enlarges the image formed by the objective lens, contributing to the overall magnification.
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Oil Immersion Objective Lens
An oil immersion lens is a high-power objective (usually 100x) used with a special immersion oil to increase resolution and clarity by reducing light refraction. It allows detailed observation of tiny structures like the cell nucleus at very high magnifications.
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Related Practice
Textbook Question
The maximum magnification of a compound microscope is (a) ________; that of an electron microscope, (b) ________. The maximum resolution of a compound microscope is (c) ________; that of an electron microscope, (d) ________. One advantage of a scanning electron microscope over a transmission electron microscope is (e) ________.
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Textbook Question
Looking at the cell of a photosynthetic microorganism, you observe the chloroplasts are green in brightfield microscopy and red in fluorescence microscopy. You conclude:
a. Chlorophyll is fluorescent
b. The magnification has distorted the image
c. You’re not looking at the same structure in both microscopes
d. The stain masked the green color
e. None of the above
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Textbook Question
Which of the following is not a functionally analogous pair of stains?
a. Nigrosin and malachite green
b. Crystal violet and carbolfuchsin
c. Safranin and methylene blue
d. Ethanol-acetone and acid-alcohol
e. All of the above pairs are functionally analogous.
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Textbook Question
Which type of microscope would be best to use to observe each of the following?
a. A stained bacterial smear
b. Unstained bacterial cells: the cells are small, and no detail is needed
c. Unstained live tissue when it is desirable to see some intracellular detail
d. A sample that emits light when illuminated with ultraviolet light
e. Intracellular detail of a cell that is 1μm long
f. Unstained live cells in which intracellular structures are shown in color
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Textbook Question
Carbolfuchsin can be used as a simple stain and a negative stain. As a simple stain, the pH is:
a. 2
b. Higher than the negative stain
c. Lower than the negative stain
d. The same as the negative stain