Cell structure and microscopy Flashcards
Put nanometers (nm), millimetrers (mm), and micrometers (µm) in order of largest to smallest.
millimeters (mm) micrometers (µm) nanometers (nm). This is because a millimeter is 1/1000 of meter, a micrometer is 1/1000000 of a meter, and a nanometer is 1/1000000000 of a meter.
How do you calculate magnification?
Magnification = Observed image size/Actual size
Eukaryotic cells have 80S ribosomes what size do Prokaryotic cells have?
70S
Which has a higher resolution; light microscope or an electron microscope?
The electron microscope because the light microscope can’t resolve between points that are closer than half the wavelength of light (250nm).
How do you calibrate a Graticule?
Use a stage micrometer scale.
What type of microscope is used to make a 3D image.?
A Scanning Electron Microscope. The image would be in black and white though, so color is added in afterwards.
What is important to remember when drawing observations?
Add a scale, the drawing taking up more than half of the space given, use a sharp pencil, identify most specific features, observe the general features first, keep looking back at specimen, and adding a title.
A Water Bear (Tardigrada) is the smallest animal in the world. It can be smaller than 0.05mm when hatched. Which type of microscope would be the best to use when trying to observe the motion of a newly hatched Water Bear?
A light Microscope as is doesn’t require the specimen to be dehydrated to prepare it. This means that it can observe living specimens unlike an electron microscope.
What does Resolution mean?
The ability to distinguish between two points.
What does Magnification mean?
How many times bigger the image is than the object.
How does a Scanning Electron Microscope work?
It sends a small beam of electrons onto a specimen. The electrons then get scatted by the electron on the surface of the specimen. This creates a 3D image of the surface.
How does a Transmission Electron Microscope work?
It transmits a beam of electrons through a thin specimen. The electrons are then focused on a screen film to create an image.
When using a light microscope, why is it recommended to use to lowest magnification before moving on to the other magnifications.
It is easier to locate the specimen on the slide using the lowest magnification as it has the biggest field of vision. That way you would not have to re position the specimen at higher magnification.
What CANNOT be observed by a light microscope out of this list? Chromosomes, Mitochondria, Vacuoles, Nucleus, 80S Ribosomes and 70S Ribosomes.
Chromosomes, 80S Ribosomes and 70S Ribosomes. Although the Mitochondria, Vacuoles and Nucleus cannot not be studied in detail using a light microscope they are still visible.
How do Light Microscopes work?
Light is transmitted through the specimen and focused to from an image.
What is the plasma membrane typically made of?
Phospholipid bilayer
Name the two things that can exit the nucleus via the nuclear pore that is then used for protein synthesis.
mRNA and ribosomes
What is the difference between a Rough Endoplasmic Reticulum and Smooth Endoplasmic Reticulum in relation to their structure?
RER contains ribosomes. SER does not.
In plant cells what does Golgi convert to make the cell wall?
Sugars
What do lysosome sacs contain?
Hydrolytic enzymes
Where are microtubules formed and broken down?
Microtubule organizing centres (MTOC) / Centrosomes or Centrioles
What are membrane-bound organelles held in place by?
Cytoskeleton
What increases the strength of the fibres in a plant’s cell wall?
Lignin
What controls the exchange of materials between the vacuole and cytoplasm?
Tonoplast
