Mechanisms of genetic exchange in bacteria

Question 1

Where are essential genes found?

Answer 1

In chromosomes

Question 2

Where are non-essential genes found?

Answer 2

In plasmids

Question 3

Plasmids replicate independent of chromosomes. True or false?

Answer 3

True

Question 4

Bacteria cannot survive without plasmids. True or false?

Answer 4

False - as they carry non-essential genes, bacteria can still survive without them, however they provide bacteria with a competitive advantage e.g. resistance

Question 5

Rate of evolution is influenced by unicellularity. True or false?

Answer 5

True

Question 6

What is transformation?

Answer 6

A genetic transfer process by which DNA is incorporated into a recipient cell and brings about genetic change

Question 7

Cells that are capable of taking up DNA and being transformed are referred to as _________

Answer 7

competent

Question 8

What can be used to force cells to take up DNA?

Answer 8

Electricity (electroporation)

Question 9

Mainly gram ______ bacteria are competent

Answer 9

positive

Question 10

What is transduction?

Answer 10

The transfer of DNA from one cell to another by a bacteriophage

Question 11

What are the two modes of transduction?

Answer 11

Specialised

Generalised

Question 12

What is generalised transduction?

Answer 12

DNA from any portion of the host genome is packaged inside the virion

Question 13

What is specialised transduction?

Answer 13

DNA from a specific region of the host chromosome is integrated directly into the virus genome

Question 14

Generalised transduction is a rare event that happens i.e. low efficiency. True or false?

Answer 14

True

Question 15

What is conjugation?

Answer 15

Mechanism of transfer that involves cell to cell contact

Question 16

Bacteria need plasmids for conjugation to take place. True or false?

Answer 16

True

Question 17

Does the recipient cell contain the conjugative plasmid?

Answer 17

No

Question 18

Sex pilus is essential for ___________. It is only produced by the donor cell

Answer 18

conjugation

Question 19

F plasmid is an _______ - it can integrate into host chromosome

Answer 19

episome

Question 20

What are cells possessing a non-integrated F plasmid called?

Answer 20

F+

Question 21

What are cells possessing an integrated F plasmid called?

Answer 21

Hfr

Question 22

What does Hfr mean?

Answer 22

High frequency of recombination

Question 23

Presence of an F plasmid results in alteration of _________ so that cell can no longer act as a recipient in conjugation, it can only be a donor

Answer 23

surface receptors

Question 24

F plasmid contains ____ genes that encode transfer function

Answer 24

tra