Oxygen is a vital element within cellular respiration. An intrinsic part of the cellular respiration cycle is the transfer or electrons through the electron transport chain, and at the end of it exists the mitochondria, in which electrons are donated to the Oxygen and combine with hydrogen ions to form water.
I suggest you to provide some options, as it's quite difficult to answer your question. Here is your answer: A long bone is covered externally with a sheath called the
periosteum, whereas the marrow cavity is lined with the <span>
endosteum</span>
. I've attached the illustration to make it clear for you
Less prey means less predatoors