Microbiology Answers

Results question regarding a serial dilution experiment testing the bacterial coliform content with a 10 fold from 10^-1 to 10^-6. Agar used was CLED, with peptone as a nutrient.

If results showed that the most concentrated form (10^-1) showed no bacteria presence after incubation. A good number colonies present (of two types) around a mid-line concentration (10^-3) and then little or no colonies on the least diluted (10^6), how can this be explained? Is this due to the nutrient competition between the bacteria?
Thank you in advance

You use phase contrast microscopy to observe a wet mount of a soil sample and a "goo" sample from the Elvis. In what ways are the potential ET microbes similar to microbes previously characterized on earth ? In what ways are they different ? How could you Determine whether the microbes present in the soul or goo samples are phylogenetically similar or distant from known micro organisms

Insects belong to the phylum

17 It is a filamentous alga. Its cells form long, thin strands that, in vast numbers, contribute to the familiar green, slimy €˜blanket weed €™ in ponds. This description best fits which of these organisms?
amoeba
spirogyra
euglena
plasmodium

Protists are classified into ___________ number of groups
3
4
5
6

1. Which is NOT TRUE regarding respiration:
A. Most ATP may not be necessary
B. Most ATP is generated oxidatively
C. The ETPs may not be necessary
D. Electrons are passed to a final inorganic electron acceptor
2. Which of the following growth situations would require the greates amount of glucose in the medium to obtain an equivalent anount of growth of the culture?
A. Aerobic respiration
B. Fermentation
C. Photosynthesis
D. Anaerobic respiration

Would you expect to use amphotericin B against a bacterial infection? A fungal infection? Offer a reason why amphotericin B has severe side effects in humans.

The mathematical model of a bacterial growth has a typical

Can a bacteriophage have only one out of the two possible life cycles ( lytic cycle and lysogenic cycle), or it can shift from one cycle to another? For example we take T2 phage, it was lytic cycle , can it also have lysogenic cycle, can it shift through cycles?

True or False
1. Gelatin is used at as concentration of 20-25%
2. A culture medium simply supplies nutrients and conditions essential for growth of a culture.
3. Since Agar is a carbohydrate, it supplies energy for the bacterial culture.
4. Most cocci have no motility.
5. Protozoa lack a cell membrane.
6. A hanging-drop preparation is used to observe Brownian motion.
7. Bacilli are the most common form of bacteria.
8. Aseptic technique will sterilize the culture medium so it can be inoculated.