Given a scientific passage and an answer, generate a question for the given answer.
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Question: Passage: Photosynthetic organisms include plants, algae, and some bacteria. Answer: photosynthetic

Answer: Plants, algae and bacteria are all examples of what type of organism?

Question: Passage: Membranes Biological membranes surround cells and serve to keep the insides separated from the outsides. They are formed of phospholipid bilayer1 s, which by definition are a double layer of fatty acid2 molecules (mostly phospholipid3 s, lipids containing lots of phosphorus). Proteins4 serve very important functions in cellular membranes. They are active transports in and out of the cell, acting as gatekeepers. They relay signals in and out of the cell. Proteins are the site of many enzymatic reactions in the cell, and play a role in regulation of cellular processes. Answer: biological membranes

Answer: What is it that surrounds cells and serve to keep the insides separated from the outsides?

Question: Passage: One of the most effective ways to cut metal is with an oxy-acetylene torch. Very high temperatures are obtained when acetylene burns in oxygen. Mixed 1:1 with oxygen, a temperature of over 3000C can be achieved. The amount of energy released is high the net heat of combustion is 1300 kJ/mole. Safety precautions need to be observed since the gas is very explosive. For welding and cutting, the oxy-acetylene torch is one of the best ways to go. Answer: metal

Answer:
An oxy-acetylene torch is an effective way to cut what?