Topic 5 Genetics Of Bacteria And Viruses

Question 1

What is the lytic cycle of a bacteriophage

Answer 1

Injects dna into host,
degrades host chromosome and makes its own protiens it needs to reassemble
Reassembles and lyses the cell and pops out

Question 2

What does:

h+
h-
r+
r-
Mean

Answer 2

Can infect two types of ecoli (wide range)
Can infect one type of ecoli (narrow range
Small plauques (small lysis)
Large plaques (big lysis)

Question 3

How do you maps the viral genome based on recombination between phages.

Answer 3

Get the possible genotypes from the cross of the phages, see which parental and which recomb the. Calculate RF

Question 4

What is generalized transduction

Answer 4

The phage undergoes lytic cycle and takes in both the donor bacteria genome and it’s own

Then it infects the recipient with the linear dna and crossing over occurs in the recipient cell

Question 5

What is cotransduction and when is it most likely to happen

Answer 5

When the phage picks up both bacterial donor genes together in one phage.

More likely if genes on donor are closer together

Question 6

The larger to cotransduction frequency, the _____ the genes are

Answer 6

Closer