This is not a joke.....

i thought fruit and plants didn't have a sex...
are there female and male bananas and melons?

Hope you don't mind me asking, what grade are you in? It's pretty basic stuff to know that the male plants have to pollonise the female plants in order for the female plant's fruits to grow (well for papaya's it's different, I guess they cross-pollonise eachother or something?) The pollonising is usually done bt wind or bees. That's why for 50% of all food humans rely on bees.. if they ever get extinct we have a big problem.

PS. Sorry if pollonising is not the right word, I'm not in the mood to look it up and I'm not a native english speaker so yeah.