The basis of the process of Natural selection is the random mutation: some organisms develop random mutations which increase their chance for survival and they survive more likely than other organisms and reproduce.
So the correct answer is:
A) Through random mutations in DNA, some pests developed a resistance to the pesticide.
I believe a valley or mountain, but I am not 100 percent sure.
The base found in RNA nucleotides, but not in DNA, is uracil.
RNA and DNA share three bases: adenine, cytosine, and guanine. However, for the fourth base, DNA has thymine while RNA
has uracil. When forming base pairs, cytosine bases are matched with guanine, while adenine bases are matched with uracil or thymine.
Normally, when a cell dies, the outside morphology changes, in other words, the cell looks different. For example, if you are growing cells that attach to a plate, when they die they are not able to attach to the bottom of the plate anymore, and they will appear floating in the medium. I am not sure of what kind of cells you are studying; if you told us it would help as to suggest ways of distinguish between live/dead cells.
