Bananas are triploid. They have three sets of each chromosome. This is unnatural. Wild bananas are diploid, just like you. Wild bananas also have big, black, oval seeds - very much like pawpaws. Not cool.
When breeders want to develop new varieties of bananas or improve existing varieties by, for example, using crosses to introduce a gene resistant for Black Sigatoka or some other disease, they need seeds. So, they induce the plant to become diploid, make the crosses and selections, and induce the new variety to, once again, take up its triploid ways.
Consider mitosis and meiosis. Speculate on how breeders might manipulate banana ploidy. What points in the cell processes could they manipulate to produce these results?
One more thing: Yes, the little black dots in a banana are shriveled, aborted seeds. Also, next time you are eating a banana, play with it - you can get it to split in three lengthwise sections. I wonder if you could get a diploid banana to do that.
