lets take for example Granddaddy purple. a clone only strain. (not real story of GDP, purely hypothetical)

lets say somebody bought a bag of weed that had seeds in it and grew out the seeds. of those seeds there was a great plant that somebody cloned and wanted to continue growing it because its a great plant that showed traits that he/she wanted.

now if that person wanted seeds they would have to cross it with a male and the seeds would be traits of both male and female plants. DIFFERENT from the clone. could be better or worse than the clone.

that is why there are clone only strains.....to preserve sought after plants