It mainly depends on the population size and technologies in the environment (Human Interference falls into that) .
The allele would be called codominant
When a dominant and recessive allele exist in an organism, only the dominant allele will be expressed. Dominant allele always mask the recessive because the gene code a protein while recessive gene doesn't. When both gene code a protein, they will be codominant and both gene will be expressed. The result could be a mixed effect. In this case, the purple is mixed color of red and blue.
Catalase is an enzyme used to accelerates chemical reactions in the human body. The performance of an enzyme depends on the pH levels. Catalase performs best at the optimum pH of 7. However, it weakens or denatures at pH levels above 10 though the range may differ on other species.
Group 13-17 contains metalloids. Boron, Silicon germanium, Arsenic, Antimony, Tellurium and Polonium are considered metalloids. They have properties of both metal and non metal. Some of the element are good semi-conductors .