This may sound terrible but less damage in a collision, and also view 
        
             
        
        
        
Sex cells will always contain half of the number of chromosomes needed for a being. So if a fishes sperm cell contains 12 chromosomes and the ovum also contains 12 chromosomes then when fused together they will have 24 chromosomes in total. 
In order for the process of the fish to even be made the sperm and ovum must be fused together. Therefore the number of chromosomes that would be found in the cells forming the gills is 24 chromosomes.
        
             
        
        
        
They have a back bone
They are cold-blooded
Breathes through skin
(extras)
they go though metamorphosis
and they hatch from eggs! <span />
        
                    
             
        
        
        
An e.coli cell without a functional laci gene is expected to always produce B-galactosidase. i found the answer to this question on a set of quizlet flash cards. i have provided the link below in case you would want to look at the flash cards for reference. 
https://quizlet.com/62335789/genetics-important-concepts-flash-cards/