Week 2 lab review

Why is it called a compound microscope?

Because it has more than one lens; it uses the ocular and objective lenses.

How should you carry a microscope?

With two hands: one hand on the arm and one hand supporting the base.

What should you be careful of when carrying a microscope?

The cord.

What power should the microscope be on when starting?

Scanning power.

What is the proper microscope storage sequence?

Remove the slide; lower the stage; put the objective on scanning power; wrap the cord; carry the microscope using the arm and base.

What is the magnification of the ocular lens?

10x.

What are the four objective lenses and their powers?

4x = scanning; 10x = low power; 40x = high power; 100x = oil immersion.

Which objective lens is the shortest?

4x scanning objective.

Which objective lens is the next shorter?

10x low-power objective.

Which objective lens is the longest?

40x high-power objective.

Which objective lens will we NOT use?

100x oil-immersion objective.

What is the formula for total magnification?

Ocular magnification x objective magnification = total magnification.

What is the total magnification with the 4x scanning objective?

40x.

What is the total magnification with the 10x low-power objective?

100x.

What is the total magnification with the 40x high-power objective?

400x.

What does the ocular eyepiece do?

It is what you look through; magnification = 10x.

What does the rotating nosepiece do?

Holds all objective lenses.

What do the slide clamps do?

They are placed on the sides of the slide to hold the slide in place.

What is the stage?

The location where the slide goes.

In what directions can the stage move?

Up, down, left, and right.

What does the coarse adjustment knob do?

It is the larger focusing knob and should be used first.

What does the fine adjustment knob do?

It is the smaller focusing knob and should be used last.

What does the iris diaphragm control?

Aperture size, which controls the amount of light going through the sample.

What is substage lighting?

The microscope's light source.

What controls the intensity of the microscope light?

The knob on the side/dimmer switch.

Where is the microscope power switch?

On the back of the microscope.

What do the stage adjustment knobs do?

Move and position the stage/slide.

What is working distance?

The distance from the top surface of the slide to the tip of the objective lens.

What unit is working distance measured in?

Millimeters (mm).

How is working distance measured?

With a ruler held vertically.

Before placing a slide on the microscope, where should the stage be?

All the way down.

Before placing a slide on the microscope, which objective should be in place?

The scanning objective.

What should you do before putting a slide on the microscope?

Look at the slide manually; put the label on the left where you can read it; note what is on the slide and its position.

How should the slide label be positioned?

Facing up, readable, and on the left side.

Which part of the slide goes into the microscope first?

The label side.

How should the slide fit inside the stage clamps?

Snugly inside the clamps, NOT underneath them.

What should you use initially to locate an object on a slide?

Scanning power and the stage knobs.

In what order should the focusing knobs be used?

Coarse adjustment first, then fine adjustment.

What is field of view?

The area/diameter of the slide visible when looking through the eyepieces.

What happens to field of view as magnification increases?

Field of view decreases.

Which has a larger field of view: low or high magnification?

Low magnification.

Which has a smaller field of view: low or high magnification?

High magnification.

At which power can field size be measured directly with a ruler?

Low power.

Why can't field size easily be measured directly at higher magnifications?

Higher magnification decreases the field of view.

What is the field-of-view equation?

Diameter A x Magnification A = Diameter B x Magnification B.

What is the rearranged field-of-view equation when Diameter B is unknown?

Diameter B = (Diameter A x Magnification A) / Magnification B.

When solving the field-of-view equation, where should the unknown go according to the professor?

Unknown on the left; everything you know on the right.

Where else can you find the field-of-view formula?

The lab manual.

Will the field-of-view calculation be tested?

Yes; it will appear on the quiz and Exam 1.

If Field A has a diameter of 3,500 at 40x and Field B is 100x, what is the diameter of Field B?

1,400.

What is a cell?

The smallest structural and functional unit of an organism.

What does the plasma membrane do?

Controls what goes into and out of the cell.

What is the nucleus?

The control center of the cell; it houses the genetic material.

What does the nuclear envelope do?

Controls what goes into and out of the nucleus.

What is chromatin?

The genetic material of the cell; uncoiled DNA.

What does DNA stand for?

Deoxyribonucleic acid.

What does the nucleolus do?

It is involved in ribosome synthesis.

What is the function of the centriole?

Attachment site for mitotic spindle fibers.

What is the function of the smooth endoplasmic reticulum?

Site of lipid synthesis.

What is the function of the rough endoplasmic reticulum?

Site of protein synthesis and modification.

What is the actual site of protein synthesis?

Ribosomes.

What does a peroxisome contain?

Detoxifying enzymes.

What does a lysosome contain?

Digestive enzymes.

What is the function of the Golgi apparatus?

Packaging and shipping for products of the endoplasmic reticulum.

What is the function of cytoskeletal elements?

Provide support and movement within the cell.

What three cytoskeletal elements are listed?

Microtubules, actin filaments, and intermediate filaments.

What is the function of mitochondria?

Produces energy in the form of ATP for the cell.

What does ATP stand for?

Adenosine triphosphate.

What is the difference between rough ER and ribosomes?

Rough ER = site of protein synthesis and modification; ribosomes = actual site of protein synthesis.

What is the difference between a peroxisome and a lysosome?

Peroxisome = detoxifying enzymes; lysosome = digestive enzymes.

What is the cell cycle?

The ordered series of growth and division events a cell undergoes from its formation until division into two identical daughter cells.

What is mitosis?

Division of the cell's nucleus and genetic material.

What is cytokinesis?

Division of the cell's cytoplasm.

What is the order of the four phases of mitosis?

Prophase → Metaphase → Anaphase → Telophase (PMAT).

What four major events occur during prophase?

DNA condenses/coils and becomes visible; nuclear envelope disappears; nucleolus disappears; centrioles move toward opposite poles and mitotic spindles appear.

What happens to DNA during prophase?

It condenses/coils and becomes visible.

What happens to the nuclear envelope during prophase?

It disappears.

What happens to the nucleolus during prophase?

It disappears.

What happens to the centrioles during prophase?

They move toward opposite poles.

What happens to mitotic spindles during prophase?

They appear.

What happens during metaphase?

Chromosomes align at the equator (metaphasic plate).

What is another name for the equator where chromosomes align during metaphase?

Metaphasic plate.

What four chromosome-related terms are shown with metaphase?

Chromatin, chromosome, sister chromatids, and centromere.

What happens during anaphase?

Chromosomes separate at the centromeres and chromatids move toward opposite poles.

Where do chromosomes separate during anaphase?

At the centromeres.

Where do chromatids move during anaphase?

Toward opposite poles.

What four major events occur during telophase?

DNA uncoils; nuclear envelope reappears; nucleolus reappears; spindles break down.

What happens to DNA during telophase?

It uncoils.

What happens to the nuclear envelope during telophase?

It reappears.

What happens to the nucleolus during telophase?

It reappears.

What happens to the mitotic spindles during telophase?

They break down.

What happens during cytokinesis?

The furrow is replaced by plasma membrane on both cells; the cytoplasm fully separates; two complete daughter cells form.

What happens to the furrow during cytokinesis?

It is replaced by plasma membrane on both cells.

What is the final result of cytokinesis?

Two complete daughter cells.

What happens to the nuclear envelope in prophase vs. telophase?

Prophase = disappears; Telophase = reappears.

What happens to the nucleolus in prophase vs. telophase?

Prophase = disappears; Telophase = reappears.

What happens to the spindle in prophase vs. telophase?

Prophase = appears; Telophase = breaks down.

What is the key difference between metaphase and anaphase?

Metaphase = chromosomes align at the equator; Anaphase = chromosomes separate at the centromeres and chromatids move toward opposite poles.

What is the difference between mitosis and cytokinesis?

Mitosis = division of nucleus/genetic material; Cytokinesis = division of cytoplasm.

What should you look for on whitefish mitosis slides?

DNA, which appears as black specks.