Phospholipid bilayers are critical components of cell membranes. The lipid bilayer acts as a barrier to the passage of molecules and ions into and out of the cell. However, an important function of the cell membrane is to allow selective passage of certain substances into and out of cells.
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mitochondrion / mitochondria coming from the apex.
Answer:
difficult
Explanation:
I guessed because I'm smart
<span>in the troposphere (the lower part of the atmosphere).</span>