The common mistake
Students often read a mark scheme after the question and think, yes, I understand that. The problem is that recognition is easier than producing the answer alone.
A better use of a mark scheme is to turn it into a checklist. Which mark-scoring idea was present? Which one was implied but never written? Which point was missing entirely?
Why marking points help
Marking points make the feedback concrete. They help the student see that a lost mark was not random: the answer omitted or underdeveloped a specific idea.
That is useful because the next question may use a different organism, circuit, graph or context. The student can practise recognising which ideas the new prompt needs without memorising the old wording.
What better feedback sounds like
Useful feedback should help the student act. A score alone says how the answer performed. A marking-point checklist says why and gives the rewrite a clear target.
This is why Question Constellation keeps the question, marking feedback, improved answer and next related question in one short flow.
A practical way to mark your own answer
Read the answer once without the mark scheme. Then check it point by point. If a point is missing, rewrite the answer rather than only adding a note in the margin.
The rewrite matters because it turns feedback into a new attempt.