The complete absence of one or more teeth (tooth agenesis) is a common trait in humans-indeed, more than $20\%$ of humans lack one or more of their third molars. However, more severe tooth agenesis, defined as the absence of six or more teeth, is less common and is frequently an inherited condition. L. Lammi and colleagues examined tooth agenesis in the Finnish family shown in the pedigree below. a. What is the most likely mode of inheritance for tooth agenesis in this family? Explain your reasoning.b. Are the two sets of twins in this family monozygotic or dizygotic twins? What is the basis of your answer?c. If IV-2 married a man who had a full set of teeth, what is the probability that their child would have tooth agenesis?d. If III-2 and III-7 married and had a child, what is the probability that their child would have tooth agenesis?

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