B.https://www.mansfieldct.org/Schools/MMS/staff/hand/genNaturalselection06.htm this is where I got my source.
In acid soils you can select the crops that can growth in this conditions (pH 6.0 - 6.5 is slightly acidic, and you can find cultures that can be cropped under this conditions). If soil is acid to highly acidic , in some areas of Northern Spain the use to increase the pH by liming the soil in a gradual / gentle way. You can find different product for liming fron rocks, wastes (from marble industries; animal bones; etc
The virus' DNA becomes a part of the host cell's DNA, and every time the host cell copies and divides, it also copies viral DNA. The viral DNA may remain inactive (a provirus) for a long time, but it can become active when it frees itself from the host's chromosome, which triggers the lytic cycle.
I forget which one is the virus' DNA
The function of the cell membrane is to protect the cell from any outer surroundings that could be harmful to it.