instruction:
Given a scientific passage and an answer, generate a question for the given answer.
question:
Passage: The hard drive is a magnetic disc that provides long-term storage for programs and data. Answer: hard drive
answer:
What device is a magnetic disc that provides long-term storage for programs and data?

question:
Passage: One dimensional motion describes objects moving in straight lines. Speed is a scalar measure of how quickly an object is moving along this line. Velocity is speed with a direction, making it a vector. If an object's velocity changes with time, the object is said to be accelerating. When restricted to one dimension, there are only two possible directions for the velocity and acceleration vectors to point in. As we'll see in the next chapters, understanding an object's acceleration is the key to understanding its motion. Answer: speed
answer:
What is the term for a scalar measure of how quickly an object is moving along this line?

question:
Passage: A mitotic spindle forms from the centrioles and passes through the nuclear membrane, which remains intact. Chromosomes attach to the mitotic spindle, which separates the chromosomes and elongates the cell. Answer: elongates the cell
answer:
A mitotic spindle forms from the centrioles and passes through the nuclear membrane, which remains intact. chromosomes attach to the mitotic spindle, which separates the chromosomes and does what?