They are basically the next step up from atoms. They are smaller living organisms. (might not be helpful but it's a start)
Seymour Benzer used phage T4 mutants, Experimental
evidence that a gene is a linear sequence of nucleotide pairs. Some regions of
chromosomes have "hot spots" for mutations. Benzer's experimental
approach to fine structure mapping of the rII locus. Generated 1612 spontaneous point mutations
and several deletions in rII locus identified two complementation groups, rIIA
and rIIB. Mapped locations of deletions
relative to each other using recombination.
Mapped locations of point mutations relative to the deletions. Tested
for recombination between all point mutations within the same complementation
group.
Animal plays important role in angiosperm reproduction either by visiting flowers for the process of pollination or eating fruits which aids in continuation of generation