Hello,
Sorry, there is an impact please. Since PMI does not blame you for incorrect response it is not advised to leave a question without response. It is strongly advised to respond all the questions. The trick is to use your first respond if you are not sure. As you are moving apply your first intention and mark the question for review so that you can come back and have a better reflection and now apply the correct response.
There is no harm to respond questions, so do your best to do not miss any questions.
Hope the above is helpful
Best regards and good luck.