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

Ex 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

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

Ex Input:
Passage: Asexual reproduction involves just one parent. It produces offspring that are genetically identical to the parent. Methods of asexual reproduction include binary fission, fragmentation, and budding. Answer: asexual

Ex Output:
What type of reproduction only involves one parent?

Ex Input:
Passage: Movable joints are also the most common type of joint in your body. Your fingers, toes, hips, elbows, and knees all provide examples of movable joints. The surfaces of bones at movable joints are covered with a smooth layer of cartilage. The cartilage reduces friction between the bones. Ligaments often cross a joint, holding two nones together. For example, there are numerous ligaments connecting the leg bones across the knee joint. Answer: movable joints

Ex Output:
What is the most common type of joint in the human body?