Question

1.There is a mutation in the luxI gene so that it can no longer function. Therefore, in high concentrations of cells, what might occur?

a.High concentrations of AHL occur and light production occurs

b.Low concentrations of AHL occur and light production occurs

c.Low concentrations of AHL occur and no light production occurs

d.High concentrations of AHL occur and no light production occurs

2. Quorum sensing is an example of

a.individual microbes working cooperatively.

b.the cumulative impact of the response of a large number of individual cells.

c.a chemical signaling system.

d.all of the choices.

Answer 1

Ans. 1) there will be low concentration of AHL as luxI gene is non functional, because AHL is the product of luxI gene. And as no AHL is produced then there will be no light production, because AHL is lower then the threshold amount which is required for luminescence.

Ans. 2) quorum sensing is a regulation of gene expression response to fluctuations in cell population density. In this, bacteria produce and release chemical signal molecule called autoinducers, eg.AHL (acylated homoserine lactone). Every cells produce signal and when they work cooperatively its impact is seen. Therefore, all the above statements are correct.