Given a scientific passage and an answer, generate a question for the given answer.
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Question: Passage: The cell membrane is made up of a phospholipid bilayer, two layers of phospholipid molecules. Notice the polar head group of the phospholipid is attached to the phosphate, and the tails are two fatty acid chains. The head group and tails are attached by a glycerol backbone. Answer: cell membrane

Answer: What basic cell structure is made up of a phospholipid bilayer and two layers of phospholipid molecules?

Question: Passage: Molecular compounds are inorganic compounds that take the form of discrete molecules . Examples include such familiar substance as water (H 2 O) and carbon dioxide (CO 2 ). These compounds are very different from ionic compounds like sodium chloride (NaCl). Ionic compounds are formed when metal atoms lose one or more of their electrons to nonmetal atoms. The resulting cations and anions are electrostatically attracted to each other. Answer: molecular compounds

Answer: What are inorganic compounds that take the form of discrete molecules called?

Question: Passage: The cytoplasm consists of watery cytosol and cell structures. It has several functions. The cytoskeleton is the "skeleton" of the cell. It helps the cell keep its shape. Answer: cytoskeleton

Answer:
What is the skeleton of the cell?