Antibiotics are ineffective against viruses because viruses do not have cells. Viruses are infectious agents that live within the cells of other living things. Antibiotics work by breaking down the cell walls of bacteria or interfering with the bacteria's ability to repair its cell's DNA, according to How Stuff Works.
Answer:
One type of control that occurs at the DNA level is the regulator genes. The regulator genes synthesize a repressor molecule that binds to the operator and stops transcription of the structural genes. Whenever there is enough amount of structural genes made, a repressor molecule will bind to the operator region and stop further transcription.
One type of control that occurs at the RNA level is RNA splicing. By this method, different proteins can be made by a single RNA transcript.
A control group take no part in any experiment, they simply do what they do normally in order to compare the results from someone who has done something differently (experiment) and someone who hasn't. Hope this helps
Answer:
it has to be B because it spreads and then gets worse
Explanation: