Question

Provide evidence with specific examples of how the microbe is changed (genotype, phenotype) and how the genetic change is acquired (mutation? HGT?)

Answer 1

the change in phenotype or genotype of a microbe is known as variation.

the genotype change is due to the change in genes by mutation or due to the loss or addition of genetic elements

example for genotype changes are

staphylococcus aureus resistance to methicillin

multi-drug resistance in mycobacterium tuberculosis

the phenotype changes are occurs due to the changes in surrounding environmental conditions during the growth of microbes

example for Pheenotype changes are

when salmonella typhi. grown in phenol agar it losses its flagella

in below 20^oC temperature listeria monocytogenes produces flagella

MUTATION

in mutation genetic changes takes place by mutagens like chemical agent and radiations

chemical agents changes normal base pair of DNA and produces Mutation

Example:

In presence of reactive oxygen species adenine converts to hypoxanthine due to deamination of bases to keto group (see uploaded image fig:1)

HORIZONTAL GENE TRANSFER

is the horizontal transfer of genetic material in between unicellular organism and multi-cellular organism

Example:

transfer of genetic information in between geminiviruses and tobacco plants