Humber Admissions Practice Test

What does complex inheritance refer to?

1. The transmission of characteristics from one parent to offspring

2. The transmission of characteristics by the joint action of multiple genes

3. Inheritance based solely on dominant and recessive alleles

4. Transmission of traits through a single set of alleles

The correct answer is: The transmission of characteristics by the joint action of multiple genes

Complex inheritance refers to the transmission of characteristics that arise from the joint action of multiple genes, often involving interactions among those genes as well as environmental factors. This form of inheritance is crucial in understanding traits that do not follow a simple Mendelian inheritance pattern. Traits such as height, skin color, or the risk of certain diseases typically result from the contributions of multiple genes, which can influence an individual’s phenotype in various ways. In contrast to the other options, which simplify the inheritance process, complex inheritance recognizes the intricate biological networks and interactions at play. For example, option A focuses solely on parental contribution without addressing the multifactorial nature of traits. Option C limits inheritance to dominant and recessive alleles, overlooking the effects of multiple alleles and gene interactions. Option D suggests that inheritance occurs through a single set of alleles, which disregards the polygenic nature of many traits. Therefore, the description of complex inheritance as the joint action of multiple genes captures the essence of how many characteristics are actually inherited.