Hello Pankaj !!

Internet is flooded with resourceful e-books. You can find out e-books for almost all topics. I am listing down some websites and apps where you can find free e-books for life sciences:

1) oodles app in playstore

2) researchgate

3) pathfinderacademy

4) barnesandnoble

5) freebookcentre

6) saveandtravel

7) stuvera

8) free-ebooks

9) crestscienceacademy

10) globalforgivenessinitiative

11) Amazon Kindle app in playstore

12) ReadMyBook app in playstore

13) Biology and Life Sciences app in playstore

Hope this helps !!