I think the most accepted Theory to make up living things is the cell theory.
The haploid male (sperm) and female (egg<span>) sex </span>cells<span>; in </span>plants<span>, formed by mitosis of haploid </span>cells<span> in the gametophyte. ... The multicellular diploid portion of the </span>plant life cycle<span> resulting from the growth, mitosis, and </span>cell<span> division of a zygote. </span>Produces<span>sporangium that store haploid spores. Google*</span>
You have give the question because we need to look the f1 generation traits first
A scientific theory may be revised overtime because it goes to the loop of science which what's the scientific theory to test several times each time a different product may be shown or every now and then a different product may be shown so therefore over time as it goes through the loop of science a scientific theory may change or be revised