The semifluid material that fills most of the cell outside the nucleus is called?

Cytoplasm is a fluid that fills most of the cell outside the nucleus

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.

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).