Hello,

No, this is not the right procedure that you only focus on one and dropped others. To do good in Mock test is well but it is not final one . To do in the actual examination need some perfection in your preparation strategy. As you are good in biology then now you should focus on the important terms on that subject. In other hand pick some topics from physics and chemistry which are important and easiear to you . Do start preparing on that note .

Best of luck.

Thank you.