Answer:
Random mutations led to evolution of pesticide resistance genes in bed bugs.
Explanation:
Random mutations in genome of bed bug imparted them the pesticide resistance. Since the bed bugs having the mutation of pesticide resistance were able to survive under presence of pesticides, this variation was favored by natural selection. The bugs with pesticide resistance transmitted this trait to their progeny. In time, the bed bug population consisted of most of the bugs having the pesticide resistance.
A fat free diet is dangerous because IT CAN RESULT IN DEFICIENCY OF ESSENTIAL FATTY ACIDS.
Essential fatty acids refers to those fatty acids that humans must eat in their foods because the body can not synthesize them and they are required for good health. There are three type of essential fatty acids, these are arachidonic, linoleic and linolenic acids. When these essential fatty acid are absent in one's diet they lead to ill health.
prevents backflow into the left atrium
A I thin because it will grow faster because its temperature is normal unlike B