How can I choose the loaded APPs in the memory RAM when using Android?

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http://stackoverflow.com – I'm not a programmer and as far as I know, Android uses as much RAM as possible, being loaded as many APPs as possible, "openning" (or getting back to them) smoother when it's necessary. My question is: Is there any way to choose which applications I DO always want to keep in memory, and which ones I NEVER want to have there? For example: Whatsapp is a very common APP. I would always want it to be there. Google Maps is always open and occupying space. I barely use it, and when I do, I don't mind to wait 5-10secs until it opens. It would be better to use that RAM for other APPs, such as my (HowTos)