Lecture 9 - David's Lecture

Question 1

What are the three major forms of horizontal gene transfer in bacteria?

Answer 1

Transformation, conjugation, transduction

Question 2

Generalised and specialised transduction both occur during what type of transduction?

Answer 2

bacteriophage mediated transduction

Question 3

In generalised transduction and specialised transduction bacterial DNA is transferred. How are they transferred in each?

Answer 3

Generalised - transfer of random sections

Specialised transfer adjacent to a prophage

Question 4

An extrachromosomal DNA molecule that replicates independently of the chromosome

Answer 4

plasmid

Question 5

Transformation involves the uptake of _____ ________by bacterial cells.

Answer 5

naked DNA

Question 6

Transformation alters what two things of a cell.

Answer 6

Genotype and phenotype

Question 7

Competency can be either ______ or _______

Answer 7

natural or artificial

Question 8

Artificially competent bacteria are prepared by incubation in ice-cold _______ _________.

Answer 8

calcium chloride.

Question 9

In the environment, transformation probably plays an important role in transferring ______ between organisms, even if they are different species.

Answer 9

genes

Question 10

Transformation is used as a common method to place __________ DNA into bacterial cells.

Answer 10

recombinant

Question 11

Basis of biotechnology

Answer 11

Transformation

Question 12

Unidirectional transfer of DNA between a donor and recipient through a conjugal bridge

Answer 12

Conjugation

Question 13

Can transfer themselves from a donor cell to a recipient cell

Answer 13

Self transmissible plasmids

Question 14

Require the help of self transmissible plasmids for transfer

Answer 14

Mobilisable plasmids

Question 15

Self transmissible plasmid genes are involved in what 2 things?

Answer 15

formation of conjugal bridge, involved in preparing and transferring DNA (eg relaxase)

Question 16

What makes a nick in one strand at the nicsite within OriT?

Answer 16

Relaxase

Question 17

What end of the DNA is attached to the relaxase?

Answer 17

5’

Question 18

Relaxase and a what is transferred to the recipient?

Answer 18

single strand of DNA

Question 19

Relaxase ________ the plasmid in the recipient

Answer 19

recyclizes. Then a complementary Strand is synthesised

Question 20

In the donor cell, DNA polymerase makes a complementary ______ at what site?

Answer 20

DNA, 3’

Question 21

Conjugation is the transfer of bacterial (plasmid) DNA by what to what contact

Answer 21

cell to cell

Question 22

Do all self transmissible plasmids possess all genes necessary for their own transfer ?

Answer 22

Yes (egF plasmid)

Question 23

What initiates DNA transfer

Answer 23

A single stranded nick in OriT by relaxase

Question 24

F plasmids can integrate into the chromosome, forming an what

Answer 24

Hfr strain

Question 25

In an Hfr strain, oriT is located on the what?

Answer 25

chromosome

Question 26

Mobilisableplasmids can not transfer themselves, but can be transferred by what?

Answer 26

other plasmids

Question 27

Mobilisable plasmids contain what type of genes involved in DNA transfer?

Answer 27

mob

Question 28

The transfer of DNA from one bacteria to another by bacteriophage

Answer 28

Transduction

Question 29

How many phages are there on the planet?

Answer 29

10 to the 31

Question 30

How many bacterial per ml of sea water

Answer 30

10 to the 7

Question 31

Lysogenic phages and lysogeny - phage DNA integrates into the bacterial ________, or exists as a __________

Answer 31

chromosome, a plasmid

Question 32

Temperate phages when integrated into chromosome do not place any burden on the _______

Answer 32

host

Question 33

Prophage state can continue for how long?

Answer 33

almost indefinitely

Question 34

Damage to DNA or infection with another phage results in phage induction and the start of a ______ ______

Answer 34

lytic cycle

Question 35

lysogenic phage often encode genes that contribute to ___________

Answer 35

virulence

Question 36

Transfer of bacterial DNA by bacteriophage

Answer 36

transduction

Question 37

Is the transduction of bacterial DNA an accidental process or a purposeful process?

Answer 37

accidental

Question 38

Are transducing particles transferred the same way as ordinary phage particles?

Answer 38

yes

Question 39

Lytic and lysogenic phages - How is general transduction and specialised transduction arisen?

Answer 39

General - from lytic cycle | Specialised - after lysogenic infection

Question 40

Is this general transduction or specialised? - Randon bacterial DNA fragments are transferred.

Answer 40

General Transduction

Question 41

Is this general transduction or specialised? Only genes close to the attachement site are transferred

Answer 41

specialised transduction

Question 42

DNA sequesnces that can 'jump' from one place to another in a genome.

Answer 42

Transposable elements (eg. different coloured corn)

Question 43

What are 3 classes of transposable elements in bacteria?

Answer 43

insertion sequences composite transposons non-composite transposons

Question 44

Transposable elements all contain ________ DNA repeat sequences at their _________

Answer 44

inverted, ends

Question 45

Where are transposable elements often found?

Answer 45

Plasmids or bacteriophages

Question 46

Insertion sequences only encode genes necessary for ____________

Answer 46

transposition

Question 47

Transposable elements that carry one or more genes in addition to those needed for transposition

Answer 47

Bacterial transposons

Question 48

DNA flanked by two IS elements of the same type

Answer 48

composite transposons

Question 49

Can composite transposons bracket additional genes?

Answer 49

Yes

Question 50

Transposable elements that carry one or more genes in addition to those needed for transposition

Answer 50

Bacterial transposons

Question 51

What is this describing: Do not contain IS elements at their ends. Do contain inverted repeats. May contain additional genes within the IR.

Answer 51

Non-composite transposons

Question 52

Often contain multiple antibiotic resistance genes

Answer 52

Transposons

Question 53

Transposons are often found on _________

Answer 53

plasmids

Question 54

What are the 2 types of gene transfer?

Answer 54

Vertical (binary fission) and Horizontal

Question 55

Uptake of naked DNA (ie. plasmid) from surroundings. Plays a role in biotechnology

Answer 55

Transformation

Question 56

Unidirectional transfer of DNA between a donor and recipient through a conjugal bridge. Self transmissible vs mobilizable plasmids.

Answer 56

Conjugation

Question 57

The transfer of DNA via a bacteriophage. Lytic vs Lysogenic. Generalised vs Specific.

Answer 57

Transduction

Question 58

DNA elements that move from one place in DNA to another in a genome

Answer 58

Transposable

Question 59

What type of gene transfer plays a role in virulence and multi-antibiotic resistance?

Answer 59

Horizontal