Fermentation and anaerobic respiration
Answer:
B) a nonsense mutation; this is because a nonsense mutation results in the change of a regular amino acid codon into a stop codon, which ceases translation. This fits with the problem's description of the protein that causes the symptoms as too short, as translation is the process by which proteins/polypeptides are created. A missense mutation would not be the answer because it still codes for an amino acid, which would not shorten the protein. A duplication of the gene would probably just lengthen the protein or not affect its length at all.
Answer:
I wasn't quite sure what virus you were referring to in your question, but here's a general answer: Viruses use their host cells' machinery to replicate themselves.
If they are a specific type of virus known as a retrovirus, they have the ability to use the host cells' enzymes to change the RNA contained within the virus into DNA (via some type of replication I suppose).
In other cases, if they contain DNA instead of RNA (that is, the virus), they can use the host cell's machinery to create RNA via enzymes involved in transcription and/or they can incorporate that DNA into the host cell's DNA. This is part of a type of viral replication cycle known as the lysogenic cycle.
In another type of viral replication cycle known as the lytic cycle, the virus simply has itself and its genome duplicated until the host cell bursts, releasing the viral material. Here, again, the virus uses the host cell's machinery to replicate itself.
It would lower the pH, raise the acidity of the water, and it would kill off a lot of marine life if it got too high. As species begin to die their predators follow, and this could cause mass extinction.
