Bca is bachelor of computer applications. You can do bca in any college even if you study biology. There is no such colleges which offer bca course to students from biology background. Eligibility criteria for bca is 10 ,12th  with 50% mark and pass in English. Students who take biology can also apply for bca. Admission is either based on merit or entrance test conducted at University level.

Bca is about computers, programming, mathematics and all. If you are from biology background, initially you feel a difficulty but after getting basics you can make up.