Explain why the milky way galaxy appears as a narrow band of light in the night sky

It is called the Milky Way because it appears as a milky band of light in the sky when you see it in a really dark area. Just as the Earth goes around the Sun, the Sun goes around the center of the Milky Way.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."