Do u have the diagram ?????
The answer to this is C because humans don't have cell walls and if you are looking at an onion it has a cell wall because it is a plant.
The raw material from which sedimentary rocks are formed is D. Weathered remains of other rocks.
Organ is an organism that is a collection of tissues and it perform a specific functions.It is found in the higher biological systems like plants, animals, and human beings. While the organelle is a part of a cell that specialized units and capable of performing a specific function for the cell. It is a very small subunits inside a cell.
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.