Android emulator is built atop qemu, so basically android emulator inherits all the features from qemu and gets more specific options for android. From the view of the command line, android emulator is more like a wrapper. It looks like:
emulator <options-for-android> -qemu <options-for-qemu>
You can refer the code in file main-emulator.c in the folder of android emulator. In there, you will see that all the options will be parsed and sent to the main function of vl-android.c, which is the entry point of a modified qemu.