Why can some cell structures only be seen with an electron microscope but not with a light microscope?

Electron microscopes use a beam of electrons instead of beams or rays of light. Living cells cannot be observed using an electron microscope because samples are placed in a vacuum. ... the scanning electron microscope (SEM) has a large depth of field so can be used to examine the surface structure of specimens.

Explanation:

No Explanation Just Pure Common Sense

Electron microscopes use electron beams rather than light beams or rays. Because samples are placed in a vacuum, living cells cannot be viewed with an electron microscope.

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).