What is happening to the number of the cells through each phase from zygote to morula to blastocyte? A. they decrease in number
B. they stay the same
C. they increase in number
D. they increase and decrease

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.

zxndjdjxjjxik no f cnnxn k is s dksoozkdkxjxjxjxj