sir I am in class 8 and I am so much mad for aiims MBBS that you can ask me any question of biology of any class and much more difficult.

HI DEAR

YOUR DOUBT HAS ALREADY BEEN ANSWERED AS YOU HAVE ASKED SAME QUESTION TWICE

THANKS

PLEASE LET US KNOW IF STILL SOME DOUBT PERSIST

dear jahnavi 
in class 8^th just u need to clear your fundamental . 
in physics , gravitation , newton 3 laws of motion and besic principle of physics , 
and in chemi all about carbon compounds and periodic table trend . 
and in bio the human physiology besic function part , they are very very imp . 
and alongwith that take part in biology and physics olympiad , they will help you to know your strong area 
REGARDS