Microscopy Quiz Review Flashcards
How will you adjust the diaphragm for a thin, translucent sample?
Reduce the light
How will you adjust the diaphragm for a thicker sample with dense structural components?
Increase the amount of light
How do you calculate the total magnification?
Magnification of eyepiece x magnification of objective
Practice: what is the total magnification for 15x eyepiece and 100x objective
1500x
Describe how to prepare cheek cells for imaging using the temporary mount technique and a stain
- swab the inside of your cheek
2.transfer the cheek swab into a drop of water on a clean slide - Use the stain Crystal-Violet Iodine Complex
We use CVI because it binds peptidoglycan (PG) which is the component in bacteria cells, good for bacteria
If you are looking at a sample under low power and its blurry, how can you focus it?
use the coarse focus knob to get the object into focus
What is the purpose of using a stain in microscopy?
- enhance visualization of the cell
-enhance cellular components under a microscope
What does methylene blue bind to?
Binds to DNA, good for the nucleus
How would methylene blue bind to a prokaryotic cell?
Everything would appear to be a dark blue color because it doesn’t have membrane bound organelles
How would methylene blue bind to a prokaryotic cell?
The nucleus would appear a dark blue color
What does iodine bind to? What would you expect it to bind in?
Iodine binds starch
you would see iodine bind in a banana
What organisms would you stain with a gram stain?
Bacteria
What is in a gram stain? (two components)
Crystal Violet and Iodine
What does gram stain bind to?
Peptidoglycan, coloring cells purple
Gram Positive Bacteria
These are bacteria that have thick peptidoglycan which is a layer of stain crystal-violet iodine is attracted to.
Gram Negative Bacteria
These are bacteria that do not have a thick layer of peptidoglycan
-crystal violet iodine complex is unable to be trapped within the structure
-the bacteria can hold the safranin having a red appearance under the microscope
What are the three shapes of bacteria?
coccus, bacillus, spirillum
What are the three presentations of bacteria?
Diplo, staphylo, strepto
How would you name a round bacteria that appears in pairs?
diplo coccus
What is the difference between prokaryotic and eukaryotic cells in terms of size?
Pro- 0.1-5.0 nanometers in diameters
Euk- 10-100 nanometers
Specialized features of prokaryotic cells
Prokaryotic- no membrane bound organelles
-u can likely only see cell walls and flagella under scope
-include bacteria and archaea
-all single celled organisms
-
Specialized features of eukaryotic cells?
-membrane bound organelles
-can see chloroplasts, nucleus, nucleolus, cell walls, mitochondria, vacuoles, cell membrane
What kind of organism is bacteria considered?
prokaryotic
What are the four that kingdoms fall under in the eukaryotic organisms?
animal, plant, fungi and protists.
How do the cell walls of bacteria, plants, and fungus differ?
bacterial cell walls are made up of peptidoglycan
plant cell walls are made up of cellulose and chitin
fungi cell walls are made up of glucans and glycoproteins
Why do animal/animal like protists not have cell walls?
because they are prokaryotic
How to tell the difference between a plant and plant-like protist
plants are multicellular, perform photosynthesis by using carbon dioxide and water, and the energy from sunlight, just like plants
plant like protists can be uni or multicellular
they do not have any true leaves, roots, or stems.
what is the difference between protists and every other kingdom of eukaryotic organisms?
they do not have any highly specialized organelles or tissues.
what are the categories’ of protists
Protozoa (animal like)
Algae (plant like)
Molds (fungi like)
Which kingdom of protists have chloroplast?
plant like protists (algae)
What does chloroplast do?
a plant cell that converts light energy into chemical energy through photosynthesis?
What is the vascular plant tissue responsible for?
provide transport pathways for water, nutrients, and signaling molecules and support a plant body against mechanical stresses.
an organism has a cell wall, and details of a cell can be viewed at 40x, what kind of organism could it be?
a plant cell
What is the flagella and cilia?
hair like structures that acts primarily as an organelle of locomotion in the cells of many living organisms
can prokaryotic organisms form tissues?
no, because prokaryotes are one-celled and two or more cells make up tissue.
when would you use a depression slide and do you need a coverslip?
when specimens which would be too thick to be observed with regular slides.
it is better use a coverslip but it isn’t mandatory.
Why don’t red blood cells have a nucleus or mitochondria?
not having a mitochondria or nucleus frees up room for the hemoglobin molecules and prevents the cell from using the oxygen it is carrying.
Why are red blood cells still eukaryotic?
Although they are lacking a nucleus in their adult life, prokaryotic cells never had a nucleus to begin with unlike the red blood cell where they did have one until adulthood.
Do dark outlines on cells always have to be cell walls?
No, it could be cytoplasm
can you see chloroplasts under a light microscope? What would it look like and in which organism could you find it?
yes, you can see it. It appears as a small green wall looking structure. You would find it in a plant cell.
How many nuclei should a cell have?
each cell should have one nuclei but there are exceptions, prokaryotic cells can lack a nuclei where as some other cells have 2 or more
Why do we not use high magnification often ?
because you can always just take a picture then enlarge it as much as you want.
can you see ribosomes under a light microscope?
ribosomes are too small to be seen and need a better kind in order to see them.
