Microbial Genetics-34

Question 1

Bacterial genome properties

Answer 1

Single circular chromosome in nucleoid

Plasmid (small circular self replicating DNA) in Cytosol (separate to chromosome).

Question 2

Horizontal gene transfer

Answer 2

Directly from one organism to another

Question 3

Vertical gene transfer

Answer 3

From parent to offspring

Question 4

Horizontal Gene transfer 3 Strategies

Answer 4

Transformation=uptake of short naked DNA fragments by naturally transformable bacteria.
Transduction=Use bacteriophages to transfer DNA from one bacterium to another.
Conjugation=Transfer of DNA via sexual pilus, requires cell to cell contact.

Question 5

Conjugation

Answer 5

Transfer of DNA via sexual pilus, requires cell to cell contact.

Question 6

Transduction

Answer 6

Use bacteriophages to transfer DNA from one bacterium to another.

Question 7

Microorganisms exchange genes to alter their virulence by

Answer 7

Horizontal gene transfer via Transduction. Lytic and Lysogenic cycles of bacteriophage replication.

Question 8

Transformation

Answer 8

uptake of short naked DNA fragments by naturally transformable bacteria.

Question 9

Draw a Bacteria

Answer 9

Fimbriae/Pili
Nucleoid 
Ribosomes
Plasma membrane
Cell wall
Capsule
Flagella
Food Granules
Bacterial Chromosome
Cytosol
Plasmid

Question 10

Draw a Bacteriophage

Answer 10

Base
tail
sheath
dna
capsid
mature head
tail fibres

Question 11

Draw Lysogenic and Lytic Replication Cycle

Answer 11

Lytic

1. ) Tail of phage on cell and injects DNA inside with bacterial chromosome.
2. ) Phage DNA Circularizes. Lytic cycle is induced.
3. ) Phage DNA and proteins are synthesized and assembled
4. ) Cell lyses releasing phages

Lysogenic

1. ) Daughter cell with prophage
2. ) Phage DNA circularizes
3. ) Phage DNA integrates into bacterial chromosome
4. ) Prophage is copied with bacterial chromosome
5. ) Many cell divisions create many infected bacteria