Do schools know what courses you don't take?

Say there was a challenging course that I didn’t take. Will they know that it was offered and question why I didn’t choose it?

If the class is listed on your school profile they will know. If not taking it means your counselor won’t check the ‘most demanding course load’ box on her rec, they will know that you didn’t take some of the most challenging classes.

Agree with the above. Also:
–Each HS sends a school profile along with the transcript that gives some information about the level of coursework available and
–Many regional admission reps are familiar with the high schools in their assigned area and have a sense of what level of coursework is available.

That said, it may not be in your best interest to take every course at your HS at the highest level. The general rule is to take the most rigorous curriculum that you can do well in. How you arrange your schedule is something you should discuss with your guidance counselor and classroom teachers.

It depends.

Lets say you took Bio, Chem, Physic and then AP Env Science. The School profile shows that AP Bio and AP Chem and AP Physics are offered. They can see you chose not to take one of those. That might not be good.

but lets say you took Bio, Chem, Physic and then AP Chem. No college is going to penalize you for not taking AP Bio and Physics too.

I think it is what is expected for the major you are taking…Did you not take AP Lang and you want to be an English major? Did you take AP Stat instead of AP Calc and you want to be an engineer? But college wouldn’t mind as much if the Engineer didn’t take AP lang or the English major didn’t take AP Calc.

So in some cases they may wonder why you didn’t take it.
If the reason was that you chose to take Honors Calc instead of AP calc because your parents are divorcing, then your GC can include that in their recommendation.