What is the difference between MAT137 and MAT135?

Hi I am entering first year Mathematical and Physical sciences and I was hoping someone here could give me some advice.

I noticed that there was two calculus', MAT137 which is full year and a lot harder as well as the split MAT135 courses which is a lot easier.

I really just want to know which is more standard or orthodox to take that would keep my options open. I also would like to know how brutal MAT137 actually is since I am planning to take other hard courses in the first year like PHY151 and the computer science courses