Lab 5

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Questions and Answers

Who coined the term 'cell' to describe the repetitive units observed in cork?

The mid-17th century scientists

A monk at a monastery

Anton van Leeuwenhoek

Robert Hooke (correct)

What was the material used to make the tube of Robert Hooke's compound microscope?

Leather (correct)

Brass

Wood

Plastic

What was the design of Anton van Leeuwenhoek's microscope?

Compound microscope with leather tube

Triple concave glass lenses

Single, high quality glass lens held in place by a brass plate (correct)

Double convex glass lenses

In what century did Robert Hooke position a piece of thinly sliced cork on his compound microscope?

17th century Signup and view all the answers

Which organelle is responsible for cytoplasmic streaming in the Elodea leaf cells?

Chloroplasts Signup and view all the answers

What is the approximate size of the chloroplasts in the Elodea leaf cells?

10 µm Signup and view all the answers

What is the function of a waxy cuticle on the upper surface of the privet leaf?

To prevent moisture loss Signup and view all the answers

Why do you not observe the small round violet structure in all of the cells of the privet leaf?

It is only present in the upper layer of cells Signup and view all the answers

What is the approximate size of a single spot on the human cheek cells slide?

15 µm Signup and view all the answers

What is the function of the chloroplasts in the Elodea leaf cells?

Energy production Signup and view all the answers

What is the main difference between the Elodea leaf cells and the human cheek cells?

Chloroplasts Signup and view all the answers

What is the function of the nuclei in the human cheek cells?

Genetic material storage Signup and view all the answers

What is the approximate size of a human cheek cell?

40 µm Signup and view all the answers

What is the function of the cell walls in the Elodea leaf cells?

To provide structural support Signup and view all the answers

What is the function of the cytoplasm in the human cheek cells?

Protein synthesis Signup and view all the answers

What is the main function of the organelle/structure stained pink on the privet leaf slide?

Structural support Signup and view all the answers

Which part of the compound microscope is responsible for controlling the amount of light reaching the specimen?

Condenser Signup and view all the answers

What is the main contribution of Theodore Schwann and Matthias Schleiden to the development of modern cell theory?

They observed and described plant and animal cells Signup and view all the answers

What is the function of the oil used for higher magnification in a compound microscope?

It increases the resolution of the specimen Signup and view all the answers

What should be done before focusing on the specimen when using a compound microscope?

Lower the stage Signup and view all the answers

What is the smallest living unit according to the cell theory?

Cell Signup and view all the answers

What is the purpose of using the provided plastic dust cover for a microscope?

To prevent dust from settling on optical components Signup and view all the answers

What happens to the field of view when increasing the magnification on a compound microscope?

It narrows Signup and view all the answers

What is the main function of the objective lens in a compound microscope?

To magnify the image of the specimen Signup and view all the answers

What is the purpose of adjusting the light intensity dial on a compound microscope?

To adjust the brightness of the light Signup and view all the answers

What is the consequence of not using both hands to carry a microscope?

Increased risk of dropping the microscope Signup and view all the answers

What is the recommended method for cleaning optical components of a microscope?

Using a cotton swab moistened with ethanol Signup and view all the answers

Why is proficiency in using a microscope crucial for scientists across disciplines?

To ensure accurate and reliable observations Signup and view all the answers

What is the formula for calculating total magnification in a compound microscope?

Total magnification = Magnification of objective lens * Magnification of ocular lens Signup and view all the answers

What is the size of ocular divisions at 100X magnification?

0.01 µm Signup and view all the answers

What does the total magnification affect in a compound microscope?

Apparent size of an object Signup and view all the answers

What is the purpose of observing cloth fibers (nylon, cotton, wool) under the microscope?

To identify their texture, arrangement, and characteristics Signup and view all the answers

What is the formula for calculating the actual size of a specimen in micrometers?

Actual size = Division size at that magnification / Total magnification Signup and view all the answers

What happens to the number of ocular divisions when using the 10x objective lens?

Increases Signup and view all the answers

What is the range of ocular division size at different magnifications?

25 µm at 4X magnification to 1 µm at 100X magnification Signup and view all the answers

What is the objective lens magnification if the total magnification is 400X and the ocular lens magnification is 10X?

40X Signup and view all the answers

What characteristic of cloth fibers is aimed to be determined through microscope observations?

Smoothness, roughness, flatness, scales, projections, and twisting Signup and view all the answers

What is the purpose of the ocular ruler with 10 units and 100 divisions?

To measure the size of objects under the microscope Signup and view all the answers

What is the relationship between the calculated letter size and the number of ocular divisions when using the 10x objective?

Remains unchanged Signup and view all the answers

Study Notes

Using a Compound Microscope: Observations and Measurements

The Leica™ DM750 microscopes have an ocular ruler with 10 units and 100 divisions.
To determine the actual size of a specimen in micrometers, note the objective lens magnification and division size at that magnification.
Total magnification is calculated by multiplying the magnification of the objective lenses by the magnification of the ocular lens (10x).
The size of ocular divisions at different magnifications range from 25 µm at 4X magnification to 1 µm at 100X magnification.
Total magnification affects the apparent size of an object under the microscope, but not its actual size.
In an experiment, the width of printed letters was measured at different font sizes using the ocular micrometer.
When using the 10x objective, the number of ocular divisions increases, but the calculated letter size remains unchanged.
Cloth fibers (nylon, cotton, wool) were observed under the microscope to identify their texture, arrangement, and characteristics.
Observations of the cloth fibers aimed to determine their 3-D arrangement and characteristics such as smoothness, roughness, flatness, scales, projections, and twisting.

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Description

Test your knowledge of using a compound microscope for observations and measurements with this quiz. Explore topics such as calculating total magnification, determining specimen size, and conducting experiments to measure objects under different magnifications. Delve into practical applications by observing and identifying characteristics of cloth fibers under the microscope.