In mice, a true-breeding female with a normal spine is crossed to a true-breeding male with a crooked spine. All of the F1 offspring have normal spines. The F1 female offspring are then crossed to true-breeding males with a crooked spine. All of the F2 offspring have normal spines. These are observations are consistent with:

Wetlands form where water and land meet. a lake with a wetland fringe can fill in with decayed plant and animal material to become a wet meadow. a pond can fill in to become a bog or fen. sediment can fill in a river marsh to become a swamp.flooding of coastal lowlands from rising sea levels has created broad coastal marshes that are protected from wave action by barrier islands or reefs. coastal wetlands also form when rivers deposit sediment as they reach the ocean. plants then take root and hold the soil firm against the forces of tides and waves.