Carbon dioxide is transported in the blood in three ways: (i) dissolved in solution; (ii) buffered with water as carbonic acid; (iii) bound to proteins, particularly haemoglobin. Source: https://academic.oup.com/bjaed/article/5/6/207/331369
Onion skin is a plant cell. And your skin cell is a animal cell.
Basically as simple all the structures in animal cell can be found in plant cells. But plant cells has some extra structure and part where doesn't exist in animal cells.
In animal cell, it contains a cytoplasm, nucleus and a cell membrane.
But in plant cell, they have chloroplast, cell wall and vacuole in additional.
<span>I am pretty sure its the diaphragm, but its not located behind the lungs its below the lungs. </span>
I believe it is D bcuz there is no more reproducing of that species so it will eventually die out.