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

Ex Input:
Passage: Bacteria lack many of the structures that eukaryotic cells contain. For example, they don't have a nucleus. They also lack membrane-bound organelles, such as mitochondria or chloroplasts. The DNA of a bacterial cell is also different from a eukaryotic cell. Bacterial DNA is contained in one circular chromosome, located in the cytoplasm. Eukaryotes have several linear chromosomes. Bacteria also have two additional unique features: a cell wall and flagella. Some bacteria also have a capsule outside the cell wall. Answer: one circular chromosome

Ex Output:
How many chromosomes do bacterial dna have?

Ex Input:
Passage: Volatile organic compounds (VOCs) are carbon compounds such as methane. VOCs are released in many human activities, such as raising livestock. Livestock wastes produce a lot of methane. Answer: methane

Ex Output:
The waste of cows releases a lot of which type of gas?

Ex Input:
Passage: Physical science can be defined as the study of matter and energy. Matter refers to all the "stuff" that exists in the universe. It includes everything you can see and many things that you cannot see, including the air around you. Energy is what gives matter the ability to move and change. Energy can take many forms, such as electricity, heat, and light. Physical science can be divided into chemistry and physics. Chemistry focuses on matter and energy at the scale of atoms and molecules. Physics focuses on matter and energy at all scales, from atoms to outer space. Answer: energy

Ex Output:
Physical science can be defined as the study of matter and what?