Similarity between Atmega162 and Arduino
The Arduino Uno has an Atmel ATmega328 onboard out of the box, but it can be replaced by a 168, and a couple others if memory serves me. Moral of the story is all Arduino boards use Atmel microcontrollers. The architecture of the AVR line is almost identical from chip to chip, down to the register content is some cases. The thing that makes Arduino easy for the hobbyists and newbies is the software. 

You're going to learn how to program micros like a professional in your class. In industry, that Arduino pseudo-code is useless. I wouldn't bother with Arduino unless you have some hobby project where you need a micro, and don't want to think about it much.