Aplants biomass mainly comes mainly from nutrients in the soil that are taken up by the plants roots

False

The mass of the plant is based on compounds made from carbon. Carbon is not absorbed from the roots, it is absorbed through the leaves in form of carbon dioxide. The process involved in the primary stage is photosynthesis. Roots absorb water and minerals or ions. These are used in reaction of the plant cells. Rest the biomass is made from glucose, which is converted into other compounds by series of reactions taking place in plant cell.

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).