Microbial Genetics

Question 1

Most complex microbial genome is a ____ genome. My can be single or double stranded ____ and ___

Answer 1

Viral
DNA
RNA

Question 2

____ sense RNA genome means it is not translatable at that time

Answer 2

Minus

Question 3

Eukaryotic cells can have ____ similar to bacteria

Answer 3

Plasmids

Question 4

Chloroplast DNA, mitochondrial DNA, and nucleus DNA can all replicate ____ of each other

Answer 4

Independently

Question 5

Prokaryotic DNA is ____ and they usually have plasmids as well

Answer 5

Circular

Question 6

Prokaryotic cells have a ____ genome than eukaryotes but still too large to fit in the cell

Answer 6

Smaller

Question 7

Bacterial chromosome replication:
____ ____ __ synthesizes the DNA.

Answer 7

DNA polymerase III

Question 8

The enzymes involved in bacterial DNA replication are just different enough to eukaryotic enzymes, that you can ___ them with antibiotics. Especially the ______ enzymes in bacterial

Answer 8

Target
Topoisomerase I

Question 9

_____ unzips the DNA helix
_____ synthesizes the RNA primer
____ ____ synthesizes the DNA
___ _____ removes the primer, repaired mismatches

Answer 9

Helicase
Primase
DNA Polymerase III
DNA Polymerase I

Question 10

Bacterial chromosome replication takes place across two ____ ____ that move it opposite directions until they get all the way across the circular structure

Answer 10

Replication forks

Question 11

Diagram of bacterial chromosome replication:

Answer 11

Question 12

The ____ ____ is when the bacterial chromosome is midway through replicating. The ___ must be resolved to detach the two chromosomes and ____ repairs the nick

Answer 12

Theta phase
Nick
Ligase

Question 13

Flow of generic information in microbes:
DNA is transcribed into _____ which is translated into ____

Answer 13

RNA
protein

Question 14

Microbes have
tRNA, mRNA, rRNA, micro RNA, interfering RNA, riboswitches, antisense RNA, similar to eukaryotes. Microbes also have ____ over the gene expression

Answer 14

Control

Question 15

Compare and contrast gene expression strategies in bacteria and eukaryotes:

Answer 15

Question 16

DNA dependent RNA polymerase (DdRp) is and enzyme that polymerizes ___ and uses ___ as a template

Answer 16

RNA
DNA

Question 17

RNA polymerase ___ makes the messenger RNA in eukaryotes. There is ___ RNA polymerase in prokaryotic cells

Answer 17

II
One

Question 18

In prokaryotes, transcripts that encode for protein are ____ meaning you can have one long RNA that can be translated into multiple types of proteins

Answer 18

Polycistronic

Question 19

In prokaryotes the transcription is controlled by variants of the ____ ___
In eukaryotes, there are ___ different types of transcription factors

Answer 19

Sigma factor
Many

Question 20

Translation is the same in prokaryotes and eukaryotes but the ___ of the ribosome is different.
Prokaryotes: ___ + ___ = 70S
Eukaryotes: ___ + ___= 80S

Answer 20

Structure
30S 50S
40S 60S

Question 21

Viral gene expression strategies:
All viruses have the ability to be able to express viral protein is completely dependent on the ___ ____.

Answer 21

Host cell

Question 22

Bacterial gene expression control:
Most ___ ____ ___ interact with DNA in a sequence specific manner. They manly bind to the ___ ___ of DNA. ____ ____ frequently are binding sites for regulatory protein, allows for better affinity

Answer 22

DNA-binding proteins
Major groove
Inverted repeats

Question 23

Outcomes of DNA binding proteins:
1. It may _____ a specific reaction on the DNA
2. They can block transcription called ___ ___
3. They can activate transcription called ___ ___

Answer 23

Catalyze
Negative regulation
Positive regulation

Question 24

_____ is a cluster of genes arranged in a linear fashion whose expression is under the control of the single operator. The operator is located downstream of the _____. Transcription is ___ blocked when a repressor binds to an operator, which is called __ ___

Answer 24

Operon
Promoter
Physically
Negative control

Question 25

Diagram of operon:

Answer 25

Question 26

____ ____ binds to the promoter region in the operon

Answer 26

RNA polymerase

Question 27

A repressor protein needs a _____ molecule to become active. The _____ is usually what the gene is transcribing, creating a ___ ___ loop.

Answer 27

Corepressor Corepressor Negative feedback

Question 28

Diagram of operon off:

Answer 28

Question 29

Another form of negative control: The lac operon is normally off because the repressor protein is already in the correct ___ to bind. When ____ is added it pulls the repressor out of the way, which is called an ____. Ensure that the operon is only being utilized when ____ is present

Answer 29

Shape Lactose Inducer Lactose

Question 30

When lactose is ____, further enzyme synthesis is not necessary so the repressor binds to the operator again

Answer 30

Depleted

Question 31

The ____ sits inbetween the promoter and the genes that need to be expressed

Answer 31

Operator

Question 32

Positive control is implemented by regulators called ___ ____. They bind to the activator binding sites on the DNA and ___ transcription. Activator protein activity is modified by ____.

Answer 32

Activator proteins Stimulate Effectors

Question 33

Promoters of positively controlled operons only ___ bind RNA polymerase. An ___ ___ helps RNA polymerase recognize the promoter by either causing a change in ___ ____ or by interacting directly with ___ ___. The activator binding site may be close to the promotor or several hundred bases away

Answer 33

Weakly Activator protein DNA structure RNA polymerase

Question 34

In positive control, the ____ is right next to the genes and the activator binding site is upstream from the promoter

Answer 34

Promotor

Question 35

The maltose activator protein binds to ___ ___ to help it find the promoter. This only occurs when ___ is present which acts as an inducer.

Answer 35

RNA polymerase Maltose

Question 36

Diagram of when the activator binding site is farther away from the promoter:

Answer 36

Question 37

Transcription is ____ to translation in bacteria. While transcription is still occurring, ribosomes bind and start translating. This is because there are no ____ ___ ____, allowing ribosomes to have excess to the newly transcribed RNA

Answer 37

Coupled Membrane bound organelles

Question 38

___ ___ is a mechanism by which bacteria assess their population density. Prokaryotes can respond to the presence of other cells of the same ____. Each species produces a specific ____ that diffuses freely and binds to activator protein that triggers ____ of specific genes

Answer 38

Quorum sensing Species Autoinducer Transcription

Question 39

Autoinducer will reach ____ concentrations inside of the cell only if ___ cells are near

Answer 39

High Many

Question 40

Quorum sensing was first discovered as mechanism, regulating light production in bacteria, including ____. The ___ operon encodes bioluminescence

Answer 40

V. Fischeri Lux

Question 41

Quorum sensing is used to create _____

Answer 41

Biofilms

Question 42

____ ___ ___ is the ability of bacteria to transfer genetic information to another bacteria. 3 different modes:

Answer 42

Horizontal gene transfer Conjugation , transform, transduction

Question 43

____ is direct transfer that takes place between two living cells using a ____

Answer 43

Conjugation Pilus

Question 44

____ is indirect transfer using free donor DNA fragments. The recipient cell is alive

Answer 44

Transformation

Question 45

____ is indirect transfer where the donor cell is lysed bacteria. Defective bacteriophage is the carrier of donor DNA to a live recipient of the same species

Answer 45

Transduction

Question 46

Horizontal gene transfer diagram:

Answer 46

Question 47

Genetic exchange: ____ is an important evolutionary process and cells have specific mechanisms for ensuring that recombination takes place. It involves DNA transfer during the process of transformation transduction

Answer 47

Recombination

Question 48

____ ___ uses donor DNA that is transferred into another cell. The donor DNA gets nicked and a single strand of that DNA finds a spot somewhere on the recipient DNA where there is a ____ sequence

Answer 48

Homologous recombination Homologous

Question 49

Diagram of genetic exchange:

Answer 49

Question 50

Transformation occurs when the donor cell ____ and DNA is ___. If this fragmented DNA bumps into a cell of the same species it can be taken into the recipient cell and perform ___ ____ for genetic exchange

Answer 50

Dies Fragmented Homologous recombination

Question 51

Transformation: ____ cells are capable of taking up DNA and being transformed. Only certain strains of bacteria are competent. Procedures are necessary to make cells competent and electricity can be used to force cells to take up DNA called _____.

Answer 51

Competent Electroporation

Question 52

Free DNA is taken up into a cell in a ____ ____ form. Only the very ____ of the strand has to have a homologous sequence with the ____ ___. It’s only looking for a place to start and then it can swap in this transformed DNA segment.

Answer 52

Single strand Beginning Bacteria DNA

Question 53

Transduction of DNA from one cell to another mediated by a ____ (virus). Two modes: _____ transduction: DNA derived from virtually any portion of the host genome is packaged inside the mature virion. _____ transduction: DNA from a specific region of the host chromosome is integrated directly in the virus genome

Answer 53

Bacteriophage Generalized Specialized

Question 54

There are two ways a bacteriophage can infect a host cell: ___ and ___ . The pathway that is takes is dependent on the species of ____ that is infecting the host.

Answer 54

Lysis Lysogeny Bacteriophage

Question 55

All bacterial phages have the ability to go through the ____ pathway. Only some bacterial phages can go through the ___ pathway. A ____ virus has the ability to perform both pathways

Answer 55

Lytic Lysogenic Temperate

Question 56

The lysogenic pathway involved the ____ of viral DNA into the host DNA. The host cell then undergoes cell division.

Answer 56

Integration

Question 57

The lytic pathway involves the viral DNA being ____ inside the host cell. Then ___ ___ are synthesized and virus particles assemble. The host cell then undergoes ___ and releases these particles

Answer 57

Replicated Coat proteins Lysis

Question 58

Diagram of lysis and lysogeny:

Answer 58

Question 59

Bacteriophage can determine the ____ of the host cell. If the host cell is ___ the virus will go the lytic pathway. If the host cell is ____ it will take the lysogenic pathway.

Answer 59

Fitness Stressed Healthy

Question 60

If a bacteriophage is in the lysogenic pathway and senses stress it will perform ____ and switch to the lytic pathway

Answer 60

Induction

Question 61

When a virus goes straight to the lytic cycle, once and awhile a segment of the ___ DNA is packaged by a virus particle. This mistake turns into a ____ particle. This is called ____ transduction

Answer 61

Host Transducing Generalized

Question 62

When a bacteriophage goes the lysogenic pathway, the virus is integrated into the host cell. If the host cell gets stressed, the virus will ___ itself out of the host genome and start to package into ___ ___. Sometimes a portion of the ___ DNA is exchanged for phage DNA and gets packed into viral particles. These can then undergo _____ transduction

Answer 62

Loop Viral particles Host Specialized

Question 63

Generalized transduction is when a bacteriophage accidentally carries ____ host DNA

Answer 63

Only

Question 64

Specialized transduction if when bacteriophages accidentally carry ____ host DNA and viral DNA after lysogenic pathway.

Answer 64

Both

Question 65

____ is a mechanism of DNA transfer in prokaryotes that requires cell to cell contact. Genes carried by the ___ ____ control conjugation. The information that the cell needs to perform conjugation is embedded in the __ ___. F stand for ___.

Answer 65

Conjugation F plasmid F plasmid Fertility

Question 66

Plasmid DNA transfer involves replication via the ___ ___ mechanism, meaning only 1 replication fork instead of 2.

Answer 66

Rolling circle

Question 67

The F plasmid is a circular DNA molecule that contains genes that regulate ___ ___. It contains several transposable elements that allow the plasmid to ___ into the host chromosome using ___ ____ (IS). It contains the ___ gene that encodes transfer functions.

Answer 67

DNA Replication Integrate Insertion sequences tra

Question 68

And __ ___ cell is a donor cell that has received the F plasmid

Answer 68

F+

Question 69

If the F plasmid is integrated into the donor cell, those cells are called ___ ____ of ____ cells.

Answer 69

High frequency of recombination (HFR)

Question 70

If a cell does not have the F plasmid it is called __ __ cell.

Answer 70

F minus

Question 71

F+ cells can make a ____ when it finds an F- cell. This allows for transfer of the F plasmid

Answer 71

Pilus

Question 72

Picture of conjugation

Answer 72

Question 73

F+ cells do not bind to another ___ cell

Answer 73

F+

Question 74

What happens if the F plasmid is integrated into the bacterial chromosome rather than sitting as a plasmid? The host chromosome becomes an ___ cell

Answer 74

Hfr

Question 75

Diagram of Hfr strains and chromosome mobilization:

Answer 75

Question 76

The integrated F plasmid still thinks it is a plasmid, when the Hfr cells function as a donor to an F- cells, it will go through the process of ____ ___ replication as if it was still a plasmid. It will be transferring genes from the ___ chromosome to an F- recipient. The plasmid will never be able to transfer everything before the host cell aborts the process. The F- cell gets what it gets, does not get the full sequence of the ___ ___.

Answer 76

Rolling circle Host F plasmid

Question 77

The F- strain will remain F- because it did not pick up all the ___ ___. But the F- cell will still pick up new properties

Answer 77

F plasmid

Question 78

When Hfr cells conjugate with F- cells, the F- cells remain ____

Answer 78

F-

Question 79

___ ___ are mobile DNA segments that move from one location to another. _____: when a transposon is excised from one location and reinserted at a second location, the number of transposons stays constant. _____: when a new copy of transposon is produced and inserted at a second location, the number of transposons present doubles.

Answer 79

Transposable elements Conservative Replicative

Question 80

Diagram of conservative and replicative transposable element:

Answer 80

Question 81

Diagram of Hfr to an F- cell. The yellow portion is the F plasmid

Answer 81