Suppose That, at the Same Time on the Same Night

question 215

Multiple Choice

Suppose that, at the same time on the same night, an astronomer sees two supernovas (exploding stars) explode in the night sky. If one is in the Andromeda Galaxy, 2 million light-years away from us, and the other is in the galaxy M82, 6 million light-years away from Earth, which of these statements concerning the actual explosion times of these supernovas is correct?

• A) It is not possible to determine which star actually exploded first because both stars are so far away.
• B) The supernova in the Andromeda Galaxy actually occurred after the one in M82.
• C) Both stars exploded at the same time because the explosions were observed at the same time.
• D) The supernova in the Andromeda Galaxy actually occurred before the one in M82.

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Definitions:

Single-Stranded Ends

The ends of DNA or RNA molecules that are not paired with a complementary sequence in double-stranded structures.

Methylate

The process of adding a methyl group to a molecule, often affecting the function or properties of the molecule.

Restriction Enzymes

Proteins produced by bacteria that cut DNA at specific sequences, widely used in molecular biology for DNA manipulation and cloning.

Viral DNA

The genetic material of a virus, composed of DNA, which contains the information necessary for the virus to replicate.