i think it has to do with how old it looks, because a star starts off as a baby little star, a different color and size. its also in a nursery with a lot of other stars, which is called a nebula. as the stars grow older and larger, they change color and drift apart. the scientists must've seen that the star has a totally different color from the baby ones, way brighter and much larger, also seeing that stars grow apart, it has not really many stars living around it for miles and miles. they must've guessed that it was probably really old.
 
        
             
        
        
        
Because it's an outer layer protecting everything inside the body, and we are practically covered in it with few opportunities / holes where bacteria can enter to cause difference to the immune system. 
        
             
        
        
        
Answer:
Cell membranes are composed of lipid molecules, which provide a flexible structure.
Explanation:
 
        
                    
             
        
        
        
2 diploid cells that are genetically identical to the parent cells
        
             
        
        
        
Answer:
Cytokinesis is the stage of the cycle when the genetic information is replicated, resulting in two daughter cells and takes place after mitosis.
Explanation: