[Campbell Biology P.453] According to Figure 19.7, which event immediately precedes the cutt... | Practice Question

According to Figure 19.7, which event immediately precedes the cutting of phage DNA by the Cas protein complex?

  • A: The entire phage DNA molecule is degraded.
  • B: The RNA transcript is processed into short RNA strands.
  • C: Complementary RNA binds to DNA from the invading phage.
  • D: Each short RNA strand binds to a Cas protein.

Explanation

Figure 19.7, Step 4, explicitly states: "Complementary RNA binds to DNA from the invading phage. The Cas protein then cuts the phage DNA." This indicates that the binding of complementary RNA to the invading phage DNA is the immediate precursor to the cutting action.