Which type of mutation always creates a stop codon?

Nonsense mutations occur when a codon that is supposed to specify an amino acid is changed to a stop codon instead. This results in a protein that is shorter than normal because it cannot finish adding all the necessary amino acids.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.