What is true about DNA mutations?

B

Explanation:

Crossing over is the process involved during meiosis of two chromosomes sharing genetic information with each other from each parent. This happens so the two daughter cells or sister chromatids have a variety of genetic information and so they are not completely identical. This leads to genetic diversity or variation.

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.

the endomembrane system i think