Is in that a difference between store-bought tomato seed, and seed departed over from drinking grocery tomatoes? I've managed to grow some honestly large tomato plants (3-4 ft....

I've managed to grow some honestly large tomato plants (3-4 ft. tall) from seed left over from the chopping board, but they own yet to produce any tomatoes (though they did flower briefly). However, some of my colleagues own already gotten tomatoes despiet their tomato plants being much smaller (they used tomato seed bought in packets). One of my friends told me this is because grocery tomatoes hold been bred to trademark commercially viable tomatoes, but are not necessarily good for growing tomato plants from. Is this true?
Answers:    here is no difference except the ones at the store are tested for a germination success rate if it is not a pious rate they arent good.

tomato seed from your tomatoes will grow, but not as many will germinate, unless you are lucky
Tomatoes produced from hybrid seed has a disposition to be infertile, so it is best to purchase the seeds from packet since they are the F1 hybrid generation, gist they are the superb product of the cross of the parents, the seeds that this F1 hybrid tomatoes will produce are inferior since they are inbred, thereby increasing the uncertainty of abnormalities.
However if your tomatoes be produced from open pollinated variety, then the seed harvested from the fruit would do as all right as the parent plants