But it was not until 1928 that penicillin, the first true antibiotic, was discovered by Alexander Fleming, Professor of Bacteriology at St. Mary's Hospital in London.
 
        
             
        
        
        
Answer:
hi sisters how are you.?? 
 
        
                    
             
        
        
        
Idk the options but it could be genetic variation
        
             
        
        
        
Answer:
Mark me as brain list plz 
Explanation:
When a trait is recessive, an individual must have two copies of a recessive allele to express the trait. Recessive alleles are denoted by a lowercase letter (a versus A). 
 
        
                    
             
        
        
        
B. group of the same species that live together.