1) In Staphylococcus epidermidis, bacillus subtilis and escherichia coli, which one has gram- positive, which one has gram-negative? Also, which organism is the largest? which one is the smallest?
2) Why will germ-positive cells more than 24 hours old stain gram-negative?
3) Can idoind steps of the Gram-staining procedure in order (omit washings), and fill in the color of gram-positive cells and gram-negative cells after each step?
4) suppose you performed a gram stain on a sample from a pure culture of bacteria and observed a field of red and purple cocci. Adjacent cell were not always the same color. What do you conclude?
5) suppose you are viewing a Gram-stained field of red rods and purple cocci through the microscope. what do you conclude?
6) considering you can't identify bacteria from a gram stain, why might a physician perform a gram stain on a sample before prescribing an antibiotic?
7) if people performed a Gram stain on human cells, what would happen?
8) what are the Gram reactions of Clostridium and Bacillus?
9) How might a capsule contribute to pathogenicity?
10) how might flagella contribute to pathogenicity?
11) of what advantage to clostridium is an endospore?
12) sketch each of the following flagellar arrangments:
a) monotrichous b) lophotrichous c) amphitrichous d) Peritrichous
13) You can see endospores by simple staining. Why not use this technique?
14) How would an endospore stain of Mycobacterium appear?
15) what type of culture medium would increase the size of a bacterial capsule?
16) Describe the microscopic appearance of encapsulated streptococcus if stained with safranin and nigrosin.
17) in the Dorner endospore stain, a smear covered with carbolfuchsin is steamed, then decolorized with acid-alcohol and counterstained with nigrosin. Describe the microscopic appearance after this procedure.