Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).
Answer:
When cells split and increase they do this very important thing in order tonmake the new cells exactly the same as the previous before them. Each cell makes more of all it's genes. Then each one.splits into two with one group of genes in each one of the new cells. During the process they make sure that all are copied correctly.
Answer:
The early stages of embryo development in fish and humans look strikingly similar while insects develop very differently compared to both fish and humans,
Explanation:
It tells you that fish and humans have very similar embryo development (fetus development) while humans and insects develop very differently. Therefore, that supports the argument that humans are more like fish than insects.
The number of electrons in the outermost shell of an atom