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

[Q]: Passage: Improving crops by selecting for certain genetic traits. The desired traits promote productivity. Recently, genetically engineered crops have been introduced. Answer: promotes productivity
[A]: What is the advantage of selecting for certain genetic traits for crops?

[Q]: Passage: The mechanical advantage of a machine is the factor by which the machine changes the input force. It equals the ratio of the output force to the input force. A wheel and axle may either increase or decrease the input force, depending on whether the input force is applied to the axle or the wheel. Answer: mechanical advantage
[A]: What is indicated by the ratio of the output force to the input force in a machine?

[Q]: Passage: The Golgi apparatus is usually made up of five to eight cup-shaped, membrane-covered stacks of discs called cisternae (singular, cisterna ), as shown in Figure below . Both plant and animal cells have a Golgi apparatus. A typical mammalian cell will have 40 to 80 of these stacks. While plant cells can have up to several hundred Golgi stacks scattered throughout the cytoplasm. In plants, the Golgi apparatus contains enzymes that synthesize some of the cell wall polysaccharides. Answer: golgi apparatus
[A]:
Which organelle is made up of 5 to eight cup shaped, membrane covered stacks of discs known as cisternae?