So the correct answer to @compmom 's question is “no” since you had multiple grades. Regardless, it does not matter - their classroom, their rules. If the teacher wants to make the entire semester’s grade hinge on one assessment, that is their right, assuming in accordance with school policies. Expect no leniency from colleges, particularly since grades based on one assessment are not uncommon in colleges, or international high schools for that matter.
But again, you won’t be rescinded.