Answer:
There are four categories for air masses: arctic, tropical, polar and equatorial. Arctic air masses form in the Arctic region and are very cold.
 
        
             
        
        
        
Answer:
Pleiotropy
Explanation:
Pleiotropy is a genetic condition in which a single gene conditions the expression of multiple phenotype. There are different types of pleiotropy depending on the underlining mechanism
- <em>gene pleiotropy</em>
 - <em>developmental pleiotropy</em>
 - <em>selectional pleiotropy</em>
 - <em>antagonistic pleiotropy </em>
 
<em>Phenylketonuria is a disease characterized by increased level of amino acid phenylalanine in the blood. It caused by mutation to the gene responsible for breaking down phenylalanine in the blood. Elevated level of phenylalanine causes other issues such as mental problems, urine coloration and reduction in skin pigmentation. This is a clear case of pleiotropy.</em>
 
        
             
        
        
        
Answer:Silicon 
Explanation: It would be considerably difficult to build computers with a gas. 
        
             
        
        
        
Proteins perform numerous functions in the cell membrane, one of which is to regulate the movement of materials, atoms of elements and other ions as they are entering and exiting the cell. These proteins that play this significant role, would be classified as transmembrane proteins, which are specific kind of intergral proteins.
        
             
        
        
        
A i think  could be wrong but i dont think so