Adolescence and Developmental Psychology Practice Test

The main idea is that the end of linear height growth during puberty happens when the growth plates at the ends of long bones fuse, a process called epiphyseal closure. These growth plates are layers of cartilage that allow bones to lengthen during childhood. As puberty progresses, sex hormones speed up growth, producing the height spurt, but eventually the plates harden and stop producing new bone in length. Once the plates fuse, further height increases stop, even though the rest of the skeleton can continue to mature in thickness and density.

This is why the opening of puberty signals the start of rapid growth, not its end. Growth plates don’t reopen once they’ve fused, so the claim that they reopen isn’t consistent with how height stops. Menarche, the first period in girls, is a puberty milestone but it isn’t the mechanism that ends height growth.