<p>You’ll have to look at the information on the UC Davis site (or whatever college you’re looking into). Every university has different ways of approaching this. Some universities allow you to switch your major at any time between any department. Some universities have limited apply periods and/or require a certain amount of prerequisites before you can be accepted into a different major.</p>
<p>Look on the website and place a call to advising if you’re still unsure.</p>