The muscle cells of people with muscular dystrophy lack a protein, called dystrophin, that maintain the sarcoplasmic reticulum of muscle cells. as a result, the sarcoplasmic reticulum allows calcium ions to leak out. why would this condition affect muscle function?

It will affect muscle contraction because it is needed for the formation of muscle contraction cross-bridge.

Explanation: During muscle contraction calcium binds to troponin, a protein complex that regulates muscle contraction by exposing the binding site of actin filament. Actin filament active site is where myosin head binds to, creating a cross-bridge using enzyme ATPase to speed the reaction. Calcium ion are needed to activate troponin movement, otherwise it stays in its inactive form blocking the active site of actin filament. Without calcium ions, troponin will not move and there will be no muscle contractions.

true, i don't really know what you're asking but from the info you provided im guessing the answer is true.

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation: