a word for someone who studies the same subject as you

[alpacinou]

Let's say Jim is doing a bachelor's degree in biology and its his second year. Alex is doing a bachelor's degree in the same subject but it's his third (last) year. Eric is going a master's degree in biology. Is there word to describe the relation these two have with Jim?

Alex is Jim's...
Eric is Jim's...

 

[Barque]

Is there word to describe the relation these two have with Jim?

If they're at the same college, Alex and Jim could call each other "coursemates" as they're doing the same course, though they're in different years. I don't think it's a very common word however. This word wouldn't apply to Eric as he's doing a master's degree. Maybe they could all call each other collegemates if they're all at the same institution; again, it isn't a commonly used word.

If they're at the same college, in India and other countries in the subcontinent, Jim and Alex might refer to Eric as their "senior" and, similarly, they'd both be Eric's juniors. Even after graduating (in India), Jim could say of Alex, "He was my senior at college".

I don't think the term is used that way in other countries. In the US or UK Jim would probably say of Alex, "He is/was a year ahead of me at college".

 

[Tarheel]

You could say Alex is a year ahead of Jim.