Answer:
actually no idea to be honest
 
        
                    
             
        
        
        
Rough endoplasmic reticulum contains ribosomes, while smooth endoplasmic reticulum does not contain ribosomes. The ribosomes are what give rough endoplasmic reticulum its characteristic "roughness."
 
        
             
        
        
        
The placenta forms at 8 weeks, and develop for 6 weeks. hope this helps 
        
             
        
        
        
"C" The only way something will make a shockwave or a sonic boom is if it's traveling faster than the speed of sound
        
             
        
        
        
Answer:
B) a nonsense mutation; this is because a nonsense mutation results in the change of a regular amino acid codon into a stop codon, which ceases translation. This fits with the problem's description of the protein that causes the symptoms as too short, as translation is the process by which proteins/polypeptides are created. A missense mutation would not be the answer because it still codes for an amino acid, which would not shorten the protein. A duplication of the gene would probably just lengthen the protein or not affect its length at all.