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

Input: Consider Input: Passage: Classification of Joints on the Basis of Function The functional classification divides joints into three categories: synarthroses, amphiarthroses, and diarthroses. A synarthrosis is a joint that is immovable. This includes sutures, gomphoses, and synchondroses. Amphiarthroses are joints that allow slight movement, including syndesmoses and symphyses. Diarthroses are joints that allow for free movement of the joint, as in synovial joints. Answer: synarthrosis

Output: What category of joints is immovable?

Input: Consider Input: Passage: Improving crops by selecting for certain genetic traits. The desired traits promote productivity. Recently, genetically engineered crops have been introduced. Answer: promotes productivity

Output: What is the advantage of selecting for certain genetic traits for crops?

Input: Consider Input: Passage: Many organisms form spores for reproduction. Some prokaryotes form spores for survival. Called endospores , they form inside prokaryotic cells when they are under stress. The stress could be UV radiation, high temperatures, or harsh chemicals. Endospores enclose the DNA and help it survive under conditions that may kill the cell. Endospores are commonly found in soil and water. They may survive for long periods of time. Answer: endospores
Output: Some prokaryotes form spores for survival called what?