Biology Lab 3 Flashcards
What part of the microscope helps you focus the oculars?
Ocular adjustment.
What part of the microscope do you put the slide sample on?
Stage
What part of the microscope holds up the oculars?
Arm
Name two types of adjustment on the lower portion of a microscope.
Coarse adjustment and fine adjustment.
How do you turn on the light on a microscope?
Light switch
What part of a microscope do the iris and stage sit on?
Base
What part of of the microscope do you use to turn the objective lens?
Revolving nosepiece
Objective lens
?
Which objective lens is the shortest?
The scanning objective.
Which adjustment knob is larger? The coarse adjustment or the fine adjustment?
The coarse adjustment
Which knob do you use to bring an image into sharper focus?
The fine adjustment knob.
Which adjustment knob should you never turn more than to complete turns?
The fine adjustment knob.
What part of a microscope do you use to reposition a slide under the objectives?
The stage controls (left/right; front/back).
The pointer (a black line) in one of the ocular’s is what?
A very tiny wire.
If a slide moves to the right, does the image move to the right or to the left?
To the left.
If an image moves to the right does the image appear the same as the actual, or is it reversed from left to right?
It is reversed and upside down.
What number is on the low power objective?
10 X
Why should you never use the course focus knob with the low power or high-power objective lenses?
It could break the slide.
What number is on the high power objective?
40 X
What is the 100 X objective (The one with the black line painted around The edge) used for?
It is the oil – immersion lens for viewing bacteria etc.
What is the total magnification using the high-power lens?
400 X
What is the total magnification using the low power lens?
100 X
Which slide would you use to practice depth of field viewing?
Silk threads slide
With which objective lens are all the threads in focus at once?
The scanning objective lens.
Which objective lens has the greatest depth of field?
10 X
What is another name for the Elodea plant?
Anachris.
What do air bubbles look like on a wet mount slide?
Round with thick dark edges.
How should you hold the coverslip when making a wet mount slide to avoid air bubbles?
At an angle.
When using a scanning lens, how do the cells of the Elodea leaf appear?
Rectanglular.
What are the numerous green structures inside the Elodea leaf?
Chloroplasts.
As the light warms a slide what do the chloroplasts appear to do?
They appear to circle around the central vacuole (the nucleus may or may not be easily visible). This is called cyclosis.
Why did you use Lugol’s Iodine (IKI), instead of water, on the onion epidermal cells?
To make the onion cells more visible.
Why do the Elodea cells have chloroplasts while the onion epidermal cells do not?
Because the Elodea are leaves. Leaves use chlorophyll, which they store in chloroplasts, to make food for plants.
What is found inside the nucleus of a cell?
Chromosomes
Where could you find human epithelial cells in your classroom?
Inside of your cheek.
What organelle is most prominent in human cheek cells?
Nucleus
How do human cells contrast with onion cells in shape?
- Human cells are smaller and more round. 2. Onion cells are more elongated and rectangular oval-ish
Why can you not see any sells when you look at your skin?
Because your cells are too small to be seen with the human eye.
What are parenchyma cells?
Unspecialized, mature plant cells with thin cell walls.
What is one thing that parenchyma cells do?
Store starch and water.
What do starch granules look like when prepared with Lugol’s Iodine?
Purple – black bodies on the slide
What might be present in a slide containing Pondwater or pond scum?
Algae, diatoms, protozoans, and multi – cellular animals.
What is Oscillatoria?
A type of bacteria that forms colonies by joining the cells side-by-side
Give an example of prokaryotic cells.
Bacteria.
Describe a prokaryotic cell.
A cell that has no nucleus or organelles.
How do you prokaryotic cells, such as bacteria, store chlorophyll?
The chlorophyll is spread throughout the cell.
How do plants store chlorophyll?
Inside chloroplasts.
What are dissection microscopes used for?
Larger objects and solid specimens that do not allow light to penetrate through them.
What is another name for a dissection microscope?
Stereomicroscope
Give an example of something you might look at on a dissection microscope.
Coin, muscle tissue
Contrast the cells of Elodea and Oscillatoria.
Elodea cells are rectangular and touch. Oscillatoria cells are long, thin and worm like. Elodea are eukaryotic and Oscillatoria are prokaryotic.
Organisms that cannot make their own food by photosynthesis are called what?
Heterotrophs.
name the organisms that you studied in lab that are heterotrophs.
Onion cells, cheek cells, potato cells
Which features of an object are visible under the dissection microscope but not visible with the naked eye?
Fine lines, small writing.
What is the maximum magnification of the dissecting microscope?
???
What is the maximum magnification of a compound microscope using the oil immersion (100 X) lens?
1000 x?
Give two examples of something that would be best observed with the compound microscope
Cells, bacteria, Pond Water, urine samples, blood samples
Give two examples of objects that would be best observed with the dissecting microscope.
Muscle tissue, paper documents, fecal samples
Name the pieces of a microscope you look through.
Oculars
