Different types of blood contact different kinds of antigens and antibodies. For example, Type A blood has A antigens and B antibodies, antibodies being the thing that fights B antigens. Type B blood has B antigens and A antibodies. So if someone with type B gets transfused with Type A blood, the person's antibodies will attack the new blood.
Backup of sewage in the preparation area or a serious pest infestation are hazards or contaminants that are grounds for immediate closure of an operation. A sewer drain backup may be among the most unpleasant experiences one can get as a house owner.
Answer:
The correct answer is "the S layer may play a role in protecting cells from viruses and predatory bacteria found in nature but not in laboratory cultures".
Explanation:
The S-layer (surface layer) is a part of the cell's envelope comprised of of identical proteins or glycoproteins that could be found in archaes and some bacterias in nature. The function of the S-layer is unknown, however the fact that is only seen in nature suggest that it may play a role in protecting cells from viruses and predatory bacteria found in nature but not in laboratory cultures. It is likely that archaes and bacteria synthesize the S-layer when they recognize viruses and predatory bacteria in nature, the S-layer is not synthesized in laboratory cultures because these pathogens are not present.
