What would happen if crossing over no longer occurred in the human meiosis

If crossing over did not occur during meiosis, there would be less genetic variation within a species.Also the species could die out due to disease and any immunity gained will die with the individual

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.