Blood type is controlled by two equally dominant genes. what type of example is this?

codominance

Explanation:

Codominance is seen in inheritance of the ABO blood group alleles. Such alleles occupy the same locus on homologous chromosome. As such, only two can be found in an individual. Allele A causes the production of antigen a on the red blood cell membranes. Allele B produces antigen b. Allele O does not produce any antigen.

Alleles A and B are codominant each other being expressed equally in the phenotype. Because only two alleles can be found in an individual, there are six possible combinations and four blood groups in the ABO blood system because A and B are codominant but dominant to O.

climate change and pollution

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.