Which infectious agent has no cells, but takes over a host cell in which it replicates and spreads into neighboring host cells

Ts assignment - snow day assignment genetic variation and natural selection natural selection relies on genetic variation. in any population of beetles, there are alleles for brown or green color. what happens to the genotype and the phenotype of the beetle population when there are distinct advantages and disadvantages due to color? order the steps that take place during natural selection in this beetle population.