Question

question 6 of 10
which explains how a probe can find a single - stranded target dna gene?
a. the probe is the second strand of dna that forms double - stranded dna with the target gene.
b. the probe carries a signaling molecule that can detect the gene.
c. the probe makes all the dna strands in an experiment radioactive.
d. the target gene matches two probes to form a three - stranded dna.

Explanation:

DNA probes are single - stranded DNA sequences. They can base - pair (hybridize) with complementary single - stranded target DNA genes. When they bind, they form double - stranded DNA. Option B is incorrect because the signaling molecule is for detection after the probe has bound (not for finding the gene). Option C is wrong as probes are specific and do not make all DNA strands radioactive. Option D is incorrect as DNA is typically double - stranded (not three - stranded in this context of probe - target binding).

Answer:

A. The probe is the second strand of DNA that forms double - stranded DNA with the target gene.