9.12.2022. + 9.14.2022. study questions (?)

Question 1

what is an operon?

Answer 1

a group of linked genes whose expression is controlled as a single unit by a common promoter

Question 2

how is an operon advantageous to prokaryotic cells?

Answer 2

allows prokaryotes to make multiple proteins all at once, it’s fast so it saves time and energy

Question 3

what is quorum sensing?
what does it accomplish?

Answer 3

communication among bacterial cells using tiny molecules. allows cells to determine the density of cells nearby.

Question 4

how is quorum sensing advantageous to prokaryotic cells?

Answer 4

some genes are only useful when expressed in critical mass.

control metabolism and behavioral activity of bacterial communities, such as biofilm formation and virulence traits. and get away from danger so that they survive when too many cells have turned on.

Question 5

how can two component systems help adapt for pathogens?

Answer 5

sense the environment and respond. they may detect low levels of something, and express a different gene than they otherwise would have.

Question 6

give an example of antigenic variation

Answer 6

Neisseria gonorrhoeae switching out which pili are being expressed/showing

Question 7

how is phase variation different from antigenic variation? what do they have in common?

Answer 7

both are mechanisms to evade the immune system. phase variation switches genes on and off, while antigenic variation modifies the genes that are being expressed leading to a different gene being expressed.

Question 8

why is HGT important?

Answer 8

genetic change, acquiring new genes, including disease-causing genes

Question 9

which mechanisms of horizontal gene transfer require homologous recombination?

Answer 9

transduction, conjugation

Question 10

what is a competent cell?

Answer 10

a cell that can uptake naked DNA

Question 11

how is an F+ cell different from an Hfr cell?

Answer 11

an F+ cell is a cell containing F plasmid. they are separate from the recipient cell.

an Hfr cell is a derivative of an F+ cell, a plasmid that has been integrated into the chromosome

Question 12

(F+) x (F-) =?
what is being transferred and via what mechanism ?

Answer 12

F+ and F+
plasmid transfer via conjugation

Question 13

how are transformation and conjugation the same?

Question 14

how are transformation and conjugation different?

Question 15

(Hfr) + (F-) = ?
what is being transferred and via what mechanism ?

Answer 15

Hfr and an F-
chromosomal DNA transfer via conjugation

Question 16

what two methods do prokaryotes use to adapt to a changing environment?

Answer 16

1. change gene expression
2. genetic change

Question 17

how do prokaryotes undergo genetic change? (2 methods)

Answer 17

1. HGT
2. mutations

Question 18

how do prokaryotes change their gene expression? (5 methods)

Answer 18

1. operons
2. quorum sensing
3. turn on/off (phase variation)
4. actually change the gene (antigenic variation)
5. 2 component systems

Question 18

how do prokaryotes change their gene expression? (5 methods)

Answer 18

1. operons
2. quorum sensing
3. turn on/off (phase variation)
4. actually change the gene (antigenic variation)
5. 2 component systems