Do high school grades matter when choosing a college major?

<p>I'm a sophomore in high school and I'm very confused about the college application process. Do high school grades give you an advantage or disadvantage based on what major you're applying for? For example, if I were to apply to the NYU College of Arts & Science as a chemistry major and I received a C or B in my high school chemistry class, will it hurt my chances or are high school grades irrelevant to your major of choice?</p>

<p>I want to be a premed student and major in a science at Rutgers NB, Drexel, Temple, NYU, Boston College, Boston University, or USC but I unfortunately received a B in my rigorous chemistry and physics classes. Will it still be possible for me to be a biochemistry, chemistry, or bio major with these grades? Will a college just flat out reject me because of my major of choice?</p>

<p>Please help! Thanks.</p>

<p>Also, is it better for me to apply as an undecided major to all of my colleges and then switch into a science major later? I’ve heard that spots run out if you do this, but I’m not 100% sure on that.</p>