Sexual production requires the sperm and egg cell
        
             
        
        
        
It controls all the activities of the cell
        
             
        
        
        
Answer:The answer is B because with 3/4 of the L trait being dominant, it’s impossible to have an offspring with the recessive trait
Explanation:
 
        
                    
             
        
        
        
The answer is Sodium Chloride 
        
                    
             
        
        
        
Answer:
The correct answer is- Immune system
Explanation:
There are physical, chemical and immunological barriers present in our body which helps us to protect from the foreign antigen. They all assist each other and helps in pathogen removal from our body.
The physical barrier includes skin, gastrointestinal tract, respiratory tract, etc which do not allow the microbe to enter the body. Chemical barriers include tear, saliva, acid in the stomach which kills microbes on the body surface.
Immune cells like macrophages, B cells kills microbes when it gets in the body. Lymphatic system also contain immune cells and helps in microbe removal.  
So the immune system is assisted by physical barrier, chemical barrier, and lymphatic system.