Meiosis and fertilization are important processes because they may most immediately result in (1) many body cells (3) immune responses (2) genetic variation (4) natural selection

(2) genetic variation

Explanation:

Meiosis is the process whereby sexually reproducing organisms produce haploid (n) gametes or sex cells via division while fertilization is the fusion of the gametes (male and female) produced as a result of meiosis to form a diploid (2n) zygote.

Meiosis is a phenomenon that is unique to only sexual reproduction and it aims at producing daughter cells that are genetically different from the parent cell. A process called CROSSING OVER, which occurs only in meiosis, enables offsprings that results from the fertilization of the gametes produced by meiosis to exhibit GENETIC VARIATION i.e. difference in genetic content from parent cell.

Uses the law of superposition to determine which rock is older or younger

Explanation:

When you say relative age of a rock, you are determining the age of a rock relative to another rock. In the case of superposition, you are determining the relative age of a layer of rock by comparing it to the position of another rock layer.

The law of superposition states that the younger rock layers will be found higher. So the deeper the layer is found, the older the rock layer will be compared to those on top of it.