Hii,Generally, any student, regardless of his study background can get into a BCA course.”Some colleges do segregate according to Maths and non maths students, as some colleges do give admissions to the students having maths as a 12th subject”. But being a science bio student wont make a student. At least in the admission process. Keeping in mind that you have a science bio background and BCA is a computer oriented course, you will or might face some problems that the students of commerce/computer and science/cs students do not face.

Having prior knowledge of computer is an advantage for the cs students, as the first month of college will be very easy for them. But for a non computer background, it is important to be regular cover up the topics. Also one has to keep interest in computer technologies and updates.

So, ultimately anyone can do a BCA course. You just have to be regular in the starting as it will be new for you.

Thanks for asking.

Hey Shiv,
Yes a Biology student can do B.tech but in specific branches offered by some colleges. Like you can do B.Tech in Biomedical Engineering, Biotechnology, or Bioinformatics offered by colleges like VIT, JUIT, etc.
But it is not suggested you do pursue a UG course again after completing your UG course with BSc or BCA, go for post-graduation in the fields can also generate great future opportunities like MBA after the courses is one most successful decision taken up by students. And waiting 4 more years hjust to qualify a Undergraduate course again have no means.
Good Luck!