question above
It varies from school to school. Some schools will see your semester grades before making an admissions decisions, while others will not even consider them even if you send them. If you perform poorly senior year below what you have previously performed in high school, then schools also have the right to withdraw their offer to you.
For regular admisison, many colleges require you to submit first semester senior year grades after you have applied as part of a mid-year report and those grades are used along with your others to decide admission. I have heard admisisons officers state in the past in relation to the mid-year report that they expect your first semester senior grades to be at least as good as prior grades and that an improvement shown by senior year grades might help a little, but a noted decline can be decisive in rejecting the applicant.
Just as many colleges do not want mid-year grades and decide regular admission base on grades through junior year. Also, if you apply early action or early deciion to colleges, the decision will be based on grades through junior year, although some want to know first quarter grades.
In any event, all colleges require you to send your final transcript after you graduate from high school, and if your senior year grades are not good, they can rescind any admission granted.
Senior year grades are important. If you’ve applied EA, colleges will look at first quarter grades and if they have any doubts about your GPA may defer you to see if you’ve remained strong through the end of the first semester.
Second semester many students relax a bit, but you should be aware acceptances are always conditional and if your GPA dips too much colleges can rescind the acceptance.