Which option best describes the functions of muscles in the body? Muscles contract and relax to move the attached bones.
Muscles attach and reattach to bones as they move.
Muscles flex and lengthen to move the attached bones.
Muscles move closer and farther away to move the attached bones.

Muscles flex and lengthen to move the attached bones.

They flec and lengthen to move the bones

answer; i believe that the correct answer is ; males are hemizygous for the x chromosome;

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.