Flu vaccines need to be revised and changed every year because the flu virus constantly mutates. Flu viruses can change in two ways: drift or shift. Antigenic drift occurs when genes of the virus slowly change during replication until the immune system no longer recognizes it. On the other hand, antigenic shift occurs when a major change in the virus happens. This usually leads to a totally different kind of virus. This is what happened during the H1N1 scare in 2009.
DNA viruses like mumps are less prone to mutation due to the presence of DNA polymerase. RNA viruses are more prone to mutation because they undergo reverse transcription to simulate the role of DNA.
The cell will undergo osmotic lysis. 3. The cell will plasmolyze.
Answer:
The minimum number of nucleotides per codon necessary to specify all 20 amino acids that are found in proteins is <u>3</u>
Explanation:
There are four nucleic acids in the RNA, adenine uracil, guanine, cytosine. Each of them combines in groups of three to give the different amino acids. In total, there are 64 different combinations of nucleic acids that codify the 20 amino acids that we need for our vital functions.
<span> D. energy storing
Photosynthesis uses energy from the sun to synthesize carbon-based molecules, that will serve as the energy for plants.</span>
