Natural selection acts directly on those gene variations for traits or phenotypes.
The phenotype of an organism is the physical characteristic and is determined by the organism's genotype. Natural selection selects the genes that produce a certain phenotype by providing suitable conditions for a certain phenotype.
        
             
        
        
        
Answer:
It depends on the mold. 
Explanation:
Blue cheese, as well as all cheeses, are molds. These are safe to eat. However, eating moldy bread will make you sick, and while it is usually not fatal, it is best to consult a doctor. If you inhale black mold spores, it will grow in your lungs and eventually kill you.
 
        
                    
             
        
        
        
Answer:
An RNA single-stranded molecule that is complementary to one of a gene's DNA strands, to be precise.
Explanation:
DNA sequences or segments code for proteins or molecules with defined functions, called genes.
 
        
             
        
        
        
I'm going with C. It may be wrong but I think it's C.
 
        
                    
             
        
        
        
The pair of characteristics that one must use to classify a fish is the presence of jaw and skeleton type. Agnatha fishes are also called jawless fishes and they lack bony skeletons. Cartilaginous fishes are composed of cartilage skeletons. Bony fishes have bony skeleton structures.