Is my plant being Macho?

I have plants in and there is two strains both strains are flowering, one type is straight flowering, but the other has flowers and little balls on it are they seeds?, is this okay why have I got balls on one lot (all from same place) and the other 2 plants (different source/place) have no balls on them. Are they still worth keeping or should I pull them out and start again?
 
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