They may look dissimilar, but they are related somehow. Points for genus and species, cultivar on the green one if you can, and their relationship to each other.
Hm... well... if this is "a pair", and the first pic is a Musa species, then surely the seeds on the second pic are also from a Musa species!!! :))) But of course not from the cultivated steril hybrid banana...
Ah no. It is a "pair" but not in the sense of a pair of species. The second plant shares a characteristic with the banana, as well as something else that I can't really hint at; it's specific to Ecuador, though. Besides, Musa seeds are honking great things. The seeds in that picture are about 5mm along the long side.
Sorry, but this new year is amazing cold here (the temperature is between -18C and -5C), so not just my plants but my brain is also frozen... :))) I don't know what could it be... :(
Think about what a Banana plant is in the Old World Tropics, and you might get a clue to what the other is in the New World Tropics. The two plants aren't genetically related other than at a most basic (they're both angiosperms) level.
I know it's not but, the 2nd looks a little like inside one of our natives the 'fingerlime'. This is more like the inside of a Paw Paw or Papaya perhaps even? (Nice one Lorax, got me scratching my head)
Chungii, you got it. Those are Papaya seeds. So now that you know what both plants are, what's the connection?
You need a pair of Papaya to set fruit (unless it's a hermaphrodite), can't say the same for bananas though, except they do have male and female flowers.
Bananas are parthenogenetic, though. The male-female flower thing is a throwback to the seeded originals. So no, that is not it.