Sterile Water – Microbiology Hw
The key terms of Microbiology Homework include, Sterile Water, Cells.
If I took 2 ml of a culture containing 4000 cells/ml and added that to a tube containing 2 ml of sterile water, the concentration of cells in the second tube would be
4000 cells/ml – correct
8000 cells
2000 cells/ml
none of these
should be 2000 cells/ml
I collect a volume of 0.1 ml of a culture. What volume of sterile water should I add to achieve a 1:10 dilution?
0.9 ml – correct
1 ml
0.1 ml
10 ml
I have a culture estimated to contain 106 colony forming units (CFU)/ml. How many 1:10 dilutions do I need to reduce the concentration to about 102 CFU/ml?
4 – correct
6
5
3
If I plate 0.1 ml of a culture is counts as a 1:10 dilution.
True – correct
False
What do we call the set of lenses nearest our eyes?
Oculars – correct
eyepieces
objectives
iris diaphragm
What is a heterotroph?
a unicellular organism
a eukaryote
a sexually reproducing organism
an organism that requires organic carbon for energy and as a source of carbon – correct
What species is Pseudomonas aeriginosa?
Pseudomonas
prokaryote
aeriginosa – correct
Why are bacteria hard to classify?
all of these – correct
most cannot be cultured in the laboratory
they lack morphological diversity
there is a high degree of lateral gene transfer among bacteria
How can DNA be used to classify bacteria?
hybridization
DNA sequencing
determine G+C ratio
all of these – correct
Classifying a bacterium is different than identifying a bacterium.
True
False
What range of number of colonies on a standard Petri plate is considered countable?
30 to 300 – correct
20 to 200
1 to 500
up to 1000
If I took 1 ml of a culture containing 7,000 cells per ml and added it to a tube containing 9 ml of sterile water, the concentration of cells in the second tube would be about
700 cells per ml – correct
7,000 cells
7,000 cells per ml
70 cells per ml
If I took 2 ml of a culture containing 4000 cells/ml and added that to a tube containing 2 ml of sterile water, the concentration of cells in the second tube would be
4000 cells/ml – correct
8000 cells
2000 cells/ml
none of these
should be 2000 cells/ml
I collect a volume of 0.1 ml of a culture. What volume of sterile water should I add to achieve a 1:10 dilution?
0.9 ml – correct
1 ml
0.1 ml
10 ml
I have a culture estimated to contain 106 colony forming units (CFU)/ml. How many 1:10 dilutions do I need to reduce the concentration to about 102 CFU/ml?
4 – correct
6
5
3
If I plate 0.1 ml of a culture is counts as a 1:10 dilution.
True – correct
False
What do we call the set of lenses nearest our eyes?
Oculars – correct
eyepieces
objectives
iris diaphragm