SO, forget what everyone else just told you. those were obviously all guesses. The internet is an amazing place, where, for instance, you can find out how to clone a tomato plant. Use a sharp blade. cut the sucker out of the crux of each branch. a clean cut is essential. Dip this cutting(or clone) into a rooting product of your choice. (liquid or powder) place the cutting in the rootcube, water, soil, or whatever fancy new thing that is popular these days...and ut a dome over it, keep it out of direct sunlight, keep it(as well as the soil) moist by misting, this is important because, without roots, your plant cannot obtain moisture, except through the leaves. by now you may know this as foliar feeding. And then, in a week or two when you are sure of the growth of roots, you can transplant. Now you can enjoy 3 or 4 plants instead of just one.
Why the heck would anyone ever want to clone a tomato?
why dont you ask yourself that question.
hope this actually helps, instead of merely critisizing.