Is it possible for a punnet square to have a heterozygous dominant / recessive? I have done my research but not able to find it. I think my teacher is tricking me, is it possible? Please help me, thank you

I'm not sure if I understand what you mean, but based on your question I think the answer is yes.

If the parents are homozygous dominant, and homozygous recessive, it would produce heterozygous dominant and recessive offspring.

If you used both parents as heterozygous, then approximately 50% of the offspring will be heterozygous as well.

I hope this helped!

Also, as a side note, if the offspring is heterozygous, it'll always show the dominant phenotype (unless it's incomplete or codominance)

frogs. the lower the ph the higher the acid content. frogs have the highest tolerance in this scenario.