Hello there!

Greetings!

Ncert books are great for building basic concepts but if you are preparing for exams like UPSC then you should go for following books for your zoology optional paper :-

• Modern Zoology by Ramesh Gupta
• Organic Evolution (Evolutionary Biology) by Veer Bala Rastogi
• Ganongs Review of Medical Physiology
• Guyton and Hall Textbook of Medical Physiology
• Cell Biology by CB Powar
• Genetics by PK Gupta
• Modern Textbook of Zoology Invertebrates by RL Kotpal
• Modern Textbook Of Zoology: Vertebrates by RL Kotpal
• Lehninger Principles of Biochemistry
• An Introduction to Embryology by AK Berry
• Ecology And Environment by PD Sharma
• Applied And Economic Zoology by VB Upadhyay and GS Shukla
• Animal Behaviour by Reena Mathur.

Thankyou