Substance a has an associated increased health risk of 12% and the increased risk associated with substance b is 18%. when studied together, the increased risk associated with being exposed to both substance a in conjunction with substance b is 60%. is the health risk associated with this combination of substances synergistic?

The diagram shows the results when two parents are crossed. the letters represent alleles for a trait that is controlled by three different genes. which best describes this inheritance pattern? multiple allele because a trait is controlled by three different genes polygenic because the offspring have alleles from both parents multiple allele because the offspring have alleles from both parents polygenic because a trait is controlled by three different genes