for the question 'under certain conditions plasmids can cross a cell membrane and enter a bacterial cell. what are they?', i have an answer of after undergoing electroporation lol because after googling & looking through the textbook i still have no idea - would anyone be able to help me out please?
Ultimately, you want a more fluid plasma membrane. And what can turn things to mush? Heat and electricity!!!!! This is achieved by what you have mentioned, electroporation!!!, where an electric current is administered to the bacterial cell. It is this electric current that alters the plasma membrane,
increasing its permeability so the plasmid can scoot through. Likewise, another method known as heat shock can be used as well. This uses knowledge of how temperature can affect the fluidity of the membrane. The bacteria and plasmids are placed into an icey solution, which is then rapidly increased to a hotter temperature, once again allowing the plasmid to penetrate the PM! I think emphasising rapid change is important here as if it were to be gradual then them cholesterol molecules will do their thing and prevent the PM from becoming permeable enough for the plasmids to enter.
So i believe the answer is what you have already mentioned, electroporation i.e the administration of an electrical current, as well as extreme , rapid temperature changes
Hope this helps