c.midrib. The petiole is a stalk arising from the stem of the plant that connects the stem to the leaf blade. In the middle of the leaf blade is the midrib, which is an extension of the petiole.
Cell membrane - the thin layer of protein and fat that surrounds the cell, but is inside the cell wall. The cell membrane is semipermeable, allowing some substances to pass into the cell and blocking others.
<span>The correct answer is C.stability is genetic and cannot be improved. This is incorrect. Just think of when you ride a bike, it's not a genetic thing and anyone can learn it if they learn how to balance their center of gravity and their movement. It's not a genetic thing so only a few chosen people can ride a bike.</span>