Botany

You can do a post graduation from special courses like M.Sc from chemistry, biochemistry, botany, zoology. You can prefer any recognised university for admission process like Delhi University, BHU, IIT-JAM for any IIT's & NITs admission. For further information, go to the official website of universities. For bio students, some universities do not prefer M.Sc chemistry. So mind it for admission.

Please refer to the link provided below for details regarding admissions in M.sc. Botany in Rajasthan University. Additionally, you can also download their brochure which contains important information regarding admissions, course eligibility, entrance exams (if any) etc.
https://www.shiksha.com/science/course/m-sc-botany-university-of-rajasthan-jaipur-31237

Yes, you are eligible to apply. You should possess MA/ M.Sc/ M.Com in the relevant subject with B.Ed.

PG Courses After B.Sc
B.Sc graduates have a wide variety of options available in terms of topics, subjects, & field . They have an option to pursue a post graduation degree in their respective field. Students can also join non-science master degree courses such as animation, management, journalism, computer technology, etc after the completion of B.Sc degree.

Dear, you can go for Master's in botany, zoology, chemistry, biotechnology, microbiology, Bioinformatics. Good luck.

Check out the article below for details :
http://www.gangte.net/2014/03/how-to-become-a-hacker.html