Answer: Bacteria gain resistance to drugs because of mutations (permanent and random changes to their DNA) which means they have changed DNA coding, giving them the ability to resist the drug fighting them off. As a result, they survive and reproduce. Over time, more and more bacteria are generated as the DNA code for resistance is passed on over generations. This results in bacteria having the ability to resist drugs. This is particularly prevalent with antibiotics.
Answer:
The Mesozoic Era is the answer
<span>Killer whales are much more common in highly productive cold water areas. These include the Atlantic, the Pacific Northwest, and the higher latitudes of the Southern Ocean.</span>
