A man who smokes heavily has developed lung cancer. The tobacco smoke has caused mutations in some of the cells in his lungs, making them unable to stop reproducing and dividing. He is worried that his children, none of whom smoke, may have inherited the lung cancer from him. Under what circumstances might his concern for his children be justified? If his smoking had already mutated the DNA in the cells in his lungs at the time his children were conceived, the mutations would have been passed to his children. If he inherited a mutation which made him more susceptible to lung cancer, it may have been present in some of the gametes he produced and passed to his children. If the mutation resulted from the duplication of a gene in his lung cells, his children would be at greater risk than if it were caused by a base pair substitution. If the smoke had caused multiple different mutations in his lung cells, it would be more likely that one or more of the mutations would be passed to his children.