NUST SAT base admission help needed...quickly

[Adorkableme]

I have to apply on SAT National seat in NUST (ASAB) for Applied Biosciences. The NUST website says that we need SAT 2 score for Biology M only. Does this mean that SAT 2 Physics and Chemistry score will not be required??? Further also that for aggregate calculation we will use a total score of 800 and not 2400??How will our merit be calculated then??

Please help as I am a little confused about this.