Thank you for your question. 

It is a positive sign that you are getting good marks in tests.

Since only a month is left for the examination, you can start timing yourself.

Start practising papers even at home and try to complete the paper within 180 minutes. 

Start brushing up your strong topics. 

Do not try to learn anything which is new as it will be very difficult for you to retain.

Polish your known skills.

Read NCERT biology again. 

Practice numericals. 

Good luck