Positive selection of t cells occur in .the thymus
        
             
        
        
        
Pick the one that gets to your heart
        
                    
             
        
        
        
Answer:
its either A or D.I remeber learning about this..Hope that helps
 
        
                    
             
        
        
        
The expected e heterozygous phenotype would be orange.
Codominance is a type of non-Mendelian inheritance in which both alleles of one genotype are simultaneously expressed. So, in this example if allele A is responsible for red flower color and allele a for yellow flower color, Aa genotype (both alleles) will give both colors  (red and yellow mixed together give orange).
 
        
             
        
        
        
Answer:
While the number of genes in an organism's DNA (red bars) varies from species to species (numbers at right), it is not always proportional to genome size (blue bars, in millions of base pairs). Note how many genes a fruit fly can squeeze out of its relatively small genome.