Flashcards in Lecture 10 Deck (56):
Define a variation
When a bacterial cell is different from its parent cell (has new characteristics)
What is is called when a bacterial cell has new characteristics when compared to the parent cells?
Name the different types of pehnotypic variations
Morphological, Cultural, and Physiological
Define a phenotypic variation
1. Temporary (can be reverted
2. Changes the expression of a gene (not a mutation)
3. Common (induced by the environment)
Are phenotypic changes permanent?
No, they are temporary and revertible
T or F- A phynotypic variation is a mutation in the gene
False, it is just a change in the expression of a gene
T or F- A phenotypic variation is a change in the expression of a gene
T or F- A phenotypic variation is unique
False, if induced by the enviroment, it will be quite common
What are some morphological variations?
Difference in sizes between culture ages, or in same species in different mediums
Which are larger, broth cultures cells or agar culture cells? Why?
Broth culture cells because the broth has more water, allowing the bacterial cells to absorb it, becoming larger
T of F- Young culture cells are smaller than old culture cells
False, young cultures are larger
T or F- Morphology refers to microscopic levels
Give an example of a cultural change
Serratia marcesens, a rod that changes color when grown in different temperature (37*C=white, 25*C=red)
At what temperature does serratia marcescens turn white?
At what temperature does serratia marcescens turn red?
What bacteria changes colors based on temperature (25*C=red, 37*C=white)?
Color change is an example of what kind of morphological change?
Give and example of a physiological change
The production of beta-galactosidase in Escherichia coli, which only happens in environments that contain lactose
Why does e.coli not constantly produce Beta Galactosidase?
To conserve energy
Do human experience physiological variations?
Yes, humans will produce alcohol dehydrosenase to break down alcohol
What organism produces alcohol dehydrosanase to break down alcohol?
Define a genotypic variation
1. Mutation (change in amino acids in DNA/RNA)
2. Permanent (nonreversable)
3. Rare (1/billion)
Are genotypic variations always helpful?
No, some can be lethal
What is a silent variation?
A genotypic variation that that no apparent effect
What do you call a genotypic variation that has no apparent effect?
A silent gene
Can genotypic variations be induces?
Yes, UV light can induce variations
How common is a genotypic variation?
Very rare, 1/billion
T of F- Genotypic variations are rare
T of F- Genotypic variations are non-permanent
T of F- Genotypic variations are always helpful
T of F- Genotypic variations are mutations
T of F- Genotypic variations are random
Give an example of a smooth bacteria
Give and example of rough bacteria
Bacillus (specifically subtilis)
Give an example of mucoid bacteria
What type (S, R, M) is e.coli?
What type (S, R, M) is Bacillus (specifically subtilis)?
What type (S, R, M) is Klebsiella pneumoniae?
What are the three forms of colonial morphological mutations?
S (smooth), R (rough), and M (mucoid)
Describe a smooth cell
Smooth, round, shiny (slime layer), virulent
Describe a rough cell
Wrinkled, dull (dry), irregular, nonvirulent
Describe a mucoid cell
Smooth, round, mucoid
T or F- a mucoid cell is smooth, round, shiny (slime layer), virulent
False, a smooth cell is smooth, round, shiny (slime layer), virulent
Smooth cells grow with what kind of morphology?
Rough cells grow with what kind of morphology?
Mucoid cells grow with what kind of morphology?
T or F- Mucoid cells grow in chains
False, they grow in singles and capsules
T or F- Rough cells grow in chains
T or F- Rough cells are virulent
T or F- What kind of cell is smooth, round, shiny, and virulent?
A smooth cell
What does a shiny layer indicate?
A slime layer
What does a dull cell indicate?
It is dry
Why are we trying to reduce the amount of anti-biotics we use in America?
To try and keep the bacteria from forming a resistance
T or F- Staphylococcus aureus will not develop a resistance to penicillin when grown in plain BHI
Is staphylococcus capable of gaining a resistance to penicillin? How?
Yes, if grown in an environment with penicillin, a single cell that has mutated a resistance can survive and reproduce penicillin resistant colonies