Answer:
Phospholipid bilayer determinates which molecules can enter or exit the cell so its purpose is to be a checker in the middle. Cell membrane determinates the structure of the cell and it is the connection to the rest that happens in a cell. 
Explanation:
Molecules can move in 2 ways: passive and active.
The only difference is the energy that is needed to do the movement.
In passive mechanisms, energy is not used, while in active transport, energy is needed. Diffusion or passive transport are moving the concentration from hight to low so the energy is not necessary. Active transport moves from low to a high concentration and it uses metabolic energy.
 
        
             
        
        
        
The probable genotype of the IV-3 with the perspective of autosomal inheritance will be A because he does not have condition A. Therefore both parents must be in condition A.
The probable genotype of IV-3 with the perspective of set=linked inheritance will be BbY this is because he has B condition. Therefore the mothers' genotype must be XBXb and the father's genotype must be XBY. 
The probability of IV-4 having condition A is 1/36
        
             
        
        
        
Because you need respiration to able to function of the rest of organs
        
             
        
        
        
Physical fitness is a medical term describing the effect of exercise on body systems and disease prevention. The body’s ability to function efficiently and effectiveness' it should contain health-related physical fitness and skill-related physical fitness. Physical fitness includes metabolic fitness and bone integrity. It is associated with person’s ability to resist hypokinetic diseases.
Optimal physical fitness is not possible without regular exercise.
 
        
             
        
        
        
Cutaneous membrane also known as the skin