Genetics: Analysis and Principles 5th Edition by Robert Brooker

Exercise 33

As a hypothetical example, a trait in mice results in mice with long tails. You initially have a true-breeding strain with normal tails and a true-breeding strain with long tails. You then make the following types of crosses:
Cross 1: When true-breeding females with normal tails are crossed to true-breeding males with long tails, all F 1 offspring have long tails.Cross 2: When true-breeding females with long tails are crossed to true-breeding males with normal tails, all F 1 offspring have normal tails.Cross 3: When F 1 females from cross 1 are crossed to true-breeding males with normal tails, all offspring have normal tails.Cross 4: When F 1 males from cross 1 are crossed to true-breeding females with long tails, half of the offspring have normal tails and half have long tails.Explain the pattern of inheritance of this trait.