To maintain pressure within plant cells and keep structure while growth ensues. Good luck, milady. *Tips his fedora*
        
             
        
        
        
Answer:
C
Explanation:
The major histocompatibility complex (MHC) is a group of genes whose function is to codify proteins that participate in the immune response, helping the system to <u>recognize foreign substances to develop an immune response</u>. 
<u>Histocompatibility or compatibility of tissue </u>is given by self-identifications molecules (antigens) located on the surface of cells, membrane, these molecules are almost <u>unique to each person</u>, letting the body to distinguish self from non-self. 
 
        
             
        
        
        
The number of protons and elctrons adds up to the mass number
 
        
             
        
        
        
Mitosis is a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth. Mitosis is important because the organism must: 
1. replace cells that have worn out or died 
2. repair tissue that is damaged 
3. add cells in order to grow 
4. make new kinds of cells in order to develop 
 
        
             
        
        
        
Pollen grain, embryos, seed coatings, and megasporangium.