Unlike the cell membrane, the cell wall a) found in all organisms b) composed of a lipid bilayer c) a flexible barrier d) usually made of tough fibers

The correct answer is D. Unlike the cell membrane, the cell wall is usually made of tough fibers. A is incorrect because while plant cells have cell walls, animal cells do not. B is incorrect because the lipid bilayer structure is found in the cell membrane not the cell wall, which allows it to be flexible and semi-permeable, which makes C incorrect because we are talking about the cell wall. The cell wall is made of tough fibers to provide support for the cell. Hope this helps! :)

Usually made of tough fibers

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