Question

Need all answers with explanations please

The CRISPR/Cas system was identified by microbiologists who were analyzing microbial genomes and discovered bacteriophage genes that were integrated into the bacterial cell's chromosome.

Answer 1

CRISPR-Cas systems can be used to modify the genomes of bacteriophages.

d). The original will be an F+ cell. When conjugation occurs, the F+ cells with A+ can act as F donors. The F plasmid DNA replicates and the newly synthesized copy of the circular F molecule is transferred to the F− recipient. So that the recipient becomes F+.

If the original cell was Hfr, the recipient will be F-.

e). Obviously the recipient cell will have A+. The copy from F+ cell will be transferred into F- cell.

f). It may occur, because genetic material can be transferred from dead cells to live cells.

g). Donor cells have a chunk of DNA called the fertility factor (or F factor). This codes for the proteins that makes up the sex pilus. It also contains a special site where DNA transfer during conjugation begins.

If the F+ factor is conjugated into dead F- cell, the plasmid from the F+ may integrate with the etb gene of F- cell and makes some F+ cell etb positive.

Thank you.