Question

In gene tests for inherited colon cancer, scientists scan a patient's DNA sample for mutated sequences using short pieces of DNA, called probes. The sequences of the probes are complementary to the mutated sequences. What happens after a probe DNA is inserted into a patient’s genome? A) The DNA probe repairs the mutated sequence. B) The DNA probe binds to its mutated counterpart and destroys it. C) The DNA probe binds to the mutated sequence and flags the mutation. Eliminate D) The DNA probe becomes an integrated part of the genome since it carries the complementary sequence to the mutated gene.

Answer 1

The answer is C) The DNA probe binds to the mutated sequence and flags the mutation.

The DNA probe does not serve to repair the mutated sequence or to destroy it or to incorporate into the genome. It only serves to show if the mutation exists. The DNA probe is complementary to the mutated sequence. If in a patient's DNA mutation exists, the DNA probe will bind to it and that way it will flag the mutation.