Recommendation letters

My child is taking non-AP science. The teacher also teaches an AP on the same subject. My child does well in the said class and if wishes to ask this teacher for a recommendation letter, how does the fact that the student not taking the AP class affect the recommendation letter? Do teachers typically compare non- AP students with AP students while writing a letter and that shows through?
Another question is that do the letters have to be from junior year teachers only? does it look bad on a college app to have letters from teachers that taught in Freshman and sophomore years?

Sophomore and Junior year teachers are generally preferred. Sophomore teachers are less than a year old and had an entire year of exposure, whereas Junior year teachers are half a year at best., so that’s a fair trade off. Freshman teachers are 18 months old - that’s a bit much.

Whether taking the following AP impacts it - that depends on the teacher. I would like to believe most teachers provide accurate reflections of a student and aren’t somehow vindictive that “he didn’t take my AP class”.

Colleges are looking for an assessment of the student from the teacher - whether the student took the AP class should be irrelevant to them also.

Thank you RichInPitt! it is helpful. The reason I mentioned sophomore/Freshman teachers is that, thanks to Covid that was the last batch of teachers that had avenues to get to know the students in a way the junior teachers have not had an opportunity to. Distance learning a whole different ball game for educators, I feel that their focus is more on learning to use the tools and organizing/adjusting themselves to the new medium of instruction. So the kid feels more comfortable asking the Sophomore teachers for a letter.

And following up on the AP class- I am concerned that the non-AP student gets compared to the AP student in terms of abilities and will be placed at a mediocre level when evaluating.