Hii,

It depends on what your syllabus is. As you have not mentioned the syllabus in question’s details, i would just speculate about the syllabus and hence would recommend specific books for them.

Note: this is for BSc in Zoology only.

Invertebrtes: R.L. Kotpal or P.S Verma (Both are equally good)

Vertebrates: R.L Kotpal (You can also buy P.S Verma if Kotpal is not available)

Ethology(Animal behaviour): V.K Aggarwal(S.chand)

Ecology: PD Sharma

Evolulion: Vir Bala Rastogi

OR

Buy a book of P.S Verma called ‘Cell Biology, Genetics, molecular biology, Evolution and Ecology’. It is a single book which will cover all the topics which it mentions (for undergraduate students).

If any other topic is in your syllabus, do let me know.

For more details about these books, ask me in comments. Thank you!