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

[Q]: Passage: Blood Blood is considered a connective tissue because it has a matrix, as shown in Figure 33.17. The living cell types are red blood cells (RBC), also called erythrocytes, and white blood cells (WBC), also called leukocytes. The fluid portion of whole blood, its matrix, is commonly called plasma. Answer: connective
[A]: What type of tissue is blood?

[Q]: Passage: Most plant cells have a large central vacuole . It can make up as much as 90 percent of a plant cell's total volume. The central vacuole is like a large storage container. It may store substances such as water, enzymes, and salts. It may have other roles as well. For example, the central vacuole helps stems and leaves hold their shape. It may also contain pigments that give flowers their colors. Answer: vacuole
[A]: Most plant cells have a large central what?

[Q]: Passage: A compass needle lines up with Earth's magnetic north pole. This is different from Earth's geographic north pole, also called true north. The geographic north pole is the top of an imaginary line. This line is the axis around which Earth rotates. The geographic north pole is much like the spindle of a spinning top. The location of the geographic north pole does not change. However, the magnetic north pole shifts in location over time. Depending on where you live, you can correct for the difference between the two poles when you use a map and a compass ( Figure below ). Answer: true north
[A]:
What is earth's geographic north pole also called?