BACTERIAL GENETICS

Question 1

single, long piece of circular, double-stranded DNA

Contain 2000 to 4000 genes.

Answer 1

Chromosome

Question 2

Small DNA circles
Replicate independently

Answer 2

Plasmids

Question 3

Call for abilities they are not born with (ability to resist antibiotics, toxins, ability to produce sex pilus) - some bacteria may acquire this from other organisms.

Genes for toxins, proteins that promote transfer

Answer 3

Plasmids

Question 4

Genetic transfer

Answer 4

Vertical gene transfer
Horizontal gene transfer

Question 5

Mother cell to offspring
Binary fission

Answer 5

Vertical Gene Transfer

Question 6

From one bacterial cell to another bacterial cell

Conjugation
Transformation
Transduction

Answer 6

Horizontal Gene Transfer

Question 7

• Bacterial mating
• Enteric, gram (-) bacteria

Answer 7

CONJUGATION

Question 8

The F+ male has a plasmid that calls for the codes for the production of the sex pilus

It can serve as the genetic donor

Sex pilus adheres to an F- (female)

One strand of the plasmid is transferred onto the female

They are now both able to copy it - 2 copies of the strand

The female has become F+ or a male bacterium, and it is now able to code for a sex pilus.

Answer 8

CONJUGATION

Question 9

The plasmid being shared is an R plasmid

Plasmid that can help bacteria resist some forms of antibiotic

Answer 9

Resistance Plasmid Conjugation

Question 10

F+ r positive donor donating the R plasmid onto an F-r negative
The recipient now becomes F+ R positive bacterium.

Once it’s shared, it is automatically replicated to produce two strands, and the recipient who was previously R-(non-resistant) and F- unable to produce sex pilus can now produce six pilus.

Answer 10

Resistance Plasmid Conjugation

Question 11

• A recombinase functioning in recombinational DNA repair in bacteria

Answer 11

RecA Protein

Question 12

occurs after the uptake of DNA fragments from the environment

When a bacterium dies, it breaks up into pieces, and some of its genetic material may be free swimming in the environment

Answer 12

TRANSFORMATION

Question 13

as a process of Gene transfer may occur between two different species

This process of gene transfer will occur
ONLY to a competent bacteria

Answer 13

Transformation

Question 14

are able to accept naked DNA from the environment.
These possess the RecA protein
- which is a critical enzyme in the process of transformation

Answer 14

Competent bacteria

Question 15

The_____ catalyzes the pairing of the single stranded
DNA with the complementary regions of the double-stranded
DNA

Answer 15

RecA protein

Question 16

Transfer of DNA Fragments from one bacterium to another by a bacteriophage

Answer 16

TRANSDUCTION

Question 17

are viruses that kills bacteria

Answer 17

Bacteriophages

Question 18

“Carry-across”

Answer 18

Transduction

Question 19

TYPES OF BACTERIOPHAGE THAT INITIATE
TRANSDUCTION

Answer 19

• Lytic or Virulent phage

• Temperate phage

Question 20

• Involves the production of viruses using a host cell to manufacture more viruses, and then the viruses would burst out of the host bacterium -> hence the name_____

Answer 20

Lytic or Virulent phage

virulent

Question 21

Replicate through the Lytic cycle

Answer 21

Lytic or Virulent phage
• T-phages

Question 22

• Undergoes replication through the lysogenic cycle

Answer 22

Temperate phage

Question 23

Involves the incorporation of the viral genome into the host cell genome creating the prophage

Answer 23

Temperate phage

Question 24

Temperate phage

Virions will now contain the_____. It has both the genetic material of the temperate phage and the bacterial host (mixture of genes)

Answer 24

prophage

Question 25

TWO FORMS OF TRANSDUCTION

Answer 25

GENERALIZED TRANSDUCTION SPECIALIZED TRANSDUCTION

Question 26

• During assembly, a genetic material is encased in a capsin. It infects another bacteria, but the genetic material it releases is that of the first bacterial host • The bacterium now has gained genetic material from another bacterial host.

Answer 26

GENERALIZED TRANSDUCTION

Question 27

When the lytic phages replicate, the capsid sometimes assembles around a small fragment of the bacterial DNA that's not viral by nature • It appears to be a virus / bacteriophage, but it carries it a bacterial DNA so it causes the transfer of one of the genetic material of another bacteria onto another bacterium

Answer 27

GENERALIZED TRANSDUCTION

Question 28

• Initiated by the temperate phage which undergoes the Lysogenic cycle as it replicates • The bacterial organism that falls prey to this type of Gene transfer undergoes lysogenic conversion

Answer 28

SPECIALIZED TRANSDUCTION

Question 29

Some bacterial DNA becomes part of the phage genome; Some phage DNA remains in the bacterial genome.

Answer 29

SPECIALIZED TRANSDUCTION

Question 30

Examples Corynebacterium diphtheria Streptococcus pyogenes Clostridium botulinum Vibriocholerae

Answer 30

Specialized transduction

Question 31

• Cells are immune to reinfection by the same phage Acquired after bacterial cells under bacterial conversion • Cells may exhibit new properties

Answer 31

LYSOGENIC CONVERSION

Question 32

Allows phage to take a bit of the adjacent bacterial DNA • There's a prophage formation When it transfers genetic material onto another bacterial host, it does not just carry viral DNA with it, Carries bacterial DNA as well -› a combination

Answer 32

LYSOGENIC CONVERSION

Question 33

The genetic material may carry a portion of the host and the temperate phage All its offsprings, the new virions carry a combination of DNA of the bacteria and that of the virus When it infects another bacteria, the bacteria has access to both phage DNA and bacterial DNA

Answer 33

LYSOGENIC CONVERSION

Question 34

any change in the DNA base sequence Example: when bacterial cells are exposed to radiation

Answer 34

Mutation

Question 35

May cause plasmids to integrate into the chromosome responsible for the spread of antibiotic resistance genes

Answer 35

Mobile Genetic Elements

Question 36

: mobile DNA segments (jumping genes)

Answer 36

Transposons

Question 37

A bacteria contains ______genes.

Answer 37

2000 to 4000

Question 38

T or F Plasmids Replicate independently

Answer 38

True

Question 39

Call for abilities they are not born with (ability to resist antibiotics, toxins, ability to produce sex pilus) – some bacteria may acquire this from other organisms

Answer 39

Plasmids

Question 40

Genes for toxins, proteins that promote transfer

Answer 40

Plasmids

Question 41

Types of horizontal gene transfer

Answer 41

Transduction Transformation Conjugation

Question 42

Conjugation happens in…

Answer 42

Enteric, gram (-) bacteria

Question 43

• It causes the host bacterium to die/lyse so the new variants can come out of the host cell ***Create virions*** using the host cell

Answer 43

Lytic or Virulent phage

Question 44

Virulent phage ■ T-phages ■ Replicate through the..

Answer 44

Lytic cycle

Question 45

Does not kill the host cell immediately, rather slowly_> will infect it first Release its genetic material and cause it to incorporate or mix with the host cell's genome. Once they mix, it is called the prophage.

Answer 45

Temperate phage or Phage Lambda

Question 46

Temperate phage ■ Phage lambda ■ Undergoes replication through the…

Answer 46

lysogenic cycle

Question 47

Bacteria that undergo specialized transduction

Answer 47

Examples ○ Corynebacterium diphtheria ○ Streptococcus pyogenes ○ Clostridium botulinum ○ Vibrio cholerae

Question 48

The bacterial chromosome, also called the____, consists of a single, closed, circular piece of dsDNA that is supercoiled to fit inside the cell.

Answer 48

genome

Question 49

It contains all the information needed for cell growth and replication

Answer 49

Genome

Question 50

______ are specific DNA sequences that code for the amino acid sequence in one protein (e.g., one gene equals one polypeptide), but this may be sliced up or combined with other polypeptides to form more than one protein.

Answer 50

Genes

Question 51

e genetic information encoded in the bacterial chromosome, many bacteria contain extra information on small circular pieces of extrachromosomal, dsDNA called______.

Answer 51

plasmids

Question 52

They are not essential for bacterial growth, so they can be gained or lost.

Answer 52

Plasmids

Question 53

Genes that code for antimicrobial resistance (and sometimes toxins or other virulence factors) are often located on plasmids.

Answer 53

Plasmids

Question 54

Plasmids are located in the______ of the cell and are selfreplicating and passed to daughter cells, similar to chromosomal DNA

Answer 54

cytoplasm

Question 55

Plasmids They also may sometimes be passed (nonsexually) from one bacterial species to another through_______ (horizontal transfer of genetic material by cell-tocell contact). This is one way drug resistance is acquired.

Answer 55

conjugation

Question 56

Mobile Genetic Elements Certain pieces of DNA are mobile and may jump from one place in the chromosome to another place. These are sometimes referred to as…

Answer 56

jumping genes

Question 57

are related mobile elements that contain additional genes. often carry drug-resistance genes and are usually located in plasmids.

Answer 57

Transposons Transposons

Question 58

______are changes that occur in the DNA code and often result in a change in the coded protein or in the prevention of its synthesis. Some _____ are silent, where a change in the DNA sequence does not result in the substitution of a different amino acid in the resulting protein

Answer 58

Mutations

Question 59

_________is a method by which genes are transferred or exchanged between homologous (similar) regions on two DNA molecules, forming new combinations of genes on a chromosome

Answer 59

Genetic recombination

Question 60

This method provides a way for organisms to obtain new combinations of biochemical pathways and adapt to changes in their environment.

Answer 60

Genetic recombination

Question 61

is the uptake and incorporation of free or naked DNA into a bacterial cell

Answer 61

Transformation

Question 62

Cells that can take up naked DNA are referred to as being______.

Answer 62

competent

Question 63

Transformation Only a few bacterial species, such as (3), do this naturally. Bacteria can be made competent in the laboratory, and transformation is the main method used to introduce genetically manipulated plasmids into bacteria, such as E. coli, during cloning procedures.

Answer 63

Streptococcus pneumoniae, Neisseria gonorrhoeae, and H. influenzae

Question 64

is the transfer of bacterial genes by a bacteriophage from one cell to another

Answer 64

Transduction

Question 65

A________ consists of a chromosome (DNA or RNA) surrounded by a protein coat. When a phage infects a bacterial cell, it injects its genome into the bacterial cell, leaving the protein coat outside.

Answer 65

bacteriophage

Question 66

_________, in which the bacteriophage DNA directs the bacterial cell to synthesize phage DNA and phage protein and package it into new phage particles. The bacterial cell eventually lyses (lytic phase), releasing a new phage that can infect other bacterial cells.

Answer 66

lytic pathway

Question 67

In some instances, the phage DNA instead becomes incorporated into the bacterial genome, where it is replicated along with the bacterial chromosomal DNA; this state is known as_______, and the phage is referred to as being_____.

Answer 67

lysogeny temperate

Question 68

During______, genes present in the phage DNA may be expressed by the bacterial cell An example of this in clinical microbiology is(3) that are lysogenized with a temperate phage carrying the gene for diphtheria toxin cause disease. Strains lacking the phage do not produce the toxin and do not cause disease. Under certain conditions, a temperate phage can be induced

Answer 68

Lysogeny C. diphtheriae. Strains of C. diphtheriae

Question 69

Strains lacking the phage do not produce the toxin and do not cause disease. Under certain conditions, a _____can be induced, the phage DNA is excised from the bacterial genome, and a lytic state occurs.

Answer 69

temperate phage

Question 70

During this process, adjacent bacterial genes may be excised with the phage DNA and packaged into the new phage. The bacterial genes may be transferred when the phage infects a new bacterium. In the field of biotechnology, phages are often used to insert cloned genes into bacteria for analysis.

Answer 70

Lytic stage

Question 71

is the transfer of genetic material from a donor bacterial strain to a recipient strain

Answer 71

Conjugation

Question 72

Conjugation In the E. coli system, the donor strain (F+) possesses a fertility factor (F factor) on a plasmid that carries the genes for conjugative transfer. The donor strain produces a hollow surface appendage called a_______, which binds to the recipient F− cell and brings the two cells in close contact.

Answer 72

sex or conjugation pilus

Question 73

When the F factor is integrated into the bacterial chromosome rather than a plasmid, there is a higher frequency of transfer of adjacent bacterial chromosomal genes. These strains are known as…

Answer 73

high-frequency recombination strains