Your instructor wants you to bring in an example of a biofilm to your lab. Which choice is the best selection for bringing in an intact biofilm for further study?
A.
Disconnecting and bringing in the old, mildewed showerhead from the showers in your dorm
B.
Scraping the mold off of the shower curtain in your dorm's bathroom into a paper cup using a butter knife
C.
Using a toothpick to scrape plaque off of your teeth and smearing it onto a slide to bring in to lab
D.
Wiping a sponge across a slimy boulder in a stream in a nearby park and bringing it in to lab
You want to examine the structure of the protein coat of a virus by microscopy. Which microscope is your best choice, and why?
A. The scanning electron microscope-it has excellent resolution and magnification, much higher than a light microscope, and can clearly visualize viruses.
B. An atomic force microscope-this has the highest resolution and magnification of the microscopes we discussed. Here, we want to visualize a subcomponent of the virus particles, so we need the best value for resolution and magnification we can possibly achieve.
C. A fluorescent microscope-this will let us tag the protein coat with colored dyes in order to visualize it using this light microscope at 1000x.
D. A bright-field light microscope-of course, we'll need to stain the viruses before we can visualize them against the bright white background at 1000x total magnification.
Mitochondria and chloroplasts are thought to have once been free-living bacteria that invaded another cell.
Indicate whether this statement is true or false.
Prokaryotes may ingest particles via phagocytosis.
Indicate whether this statement is true or false.
Cilia and flagella project from the cell and are not covered by cytoplasmic membrane.
Indicate whether this statement is true or false.
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