[Campbell Biology P.472] If a target mRNA sequence is 5′...CUCAUCACCGGC...3′, what would be ... | Practice Question

If a target mRNA sequence is 5′...CUCAUCACCGGC...3′, what would be the complementary DNA probe sequence synthesized for in situ hybridization according to the text?

  • A: 5′...GAGGTAGGCCGG...3′
  • B: 3′...GAGTAGTGGCCG...5′
  • C: 5′...GUGAUGUGGCCG...3′
  • D: 3′...CTCTGCAGGTTA...5′

Explanation

The mRNA sequence is 5′...CUCAUCACCGGC...3′. For a complementary DNA probe, C pairs with G, U pairs with A, A pairs with T, and G pairs with C. The text provides an example where the probe is synthesized in the 3' to 5' direction to be complementary to the mRNA. Therefore, 3′...GAGTAGTGGCCG...5′ is the correct DNA probe sequence.