Given a scientific passage and an answer, generate a question for the given answer.

Ex Input:
Passage: Regulation of transcription in prokaryotes typically involves operons. An operon is a region of DNA that consists of one or more genes that encode the proteins needed for a specific function. The operon also includes a promoter and an operator. The operator is a region of the operon where regulatory proteins bind. It is located near the promoter and helps regulate transcription of the operon genes. Answer: operon

Ex Output:
Which region of dna consists of one or more genes that encode the proteins needed for a specific function?

Ex Input:
Passage: Population density is the average number of individuals in a population per unit of area or volume. For example, a population of 100 insects that live in an area of 100 square meters has a density of 1 insect per square meter. If the same population lives in an area of only 1 square meter, what is its density? Which population is more crowded? How might crowding affect the health of a population?. Answer: population density

Ex Output:
What is the term for the average number of individuals in a population per unit of area or volume?

Ex Input:
Passage: Underground mining is used to recover ores that are deeper into Earth's surface. Miners blast and tunnel into rock to gain access to the ores. An underground ore deposit can be approached from above, below, or sideways. The direction depends on the placement of the ore body, its depth, the concentration of ore, and the strength of the surrounding rock. An example of an underground mine can be seen below ( Figure below ). Answer: underground

Ex Output:
What type of mining is used to recover ores that are deeper into earth's surface?