Question

Assertion (A): In molecular diagnosis, single stranded DNA or RNA tagged with radioactive molecule is called a probe.

Reason (R): A probe always searches and hybridises with its complementary DNA in a clone of cells.

Options

• Both (A) and (R) are true and (R) is the correct explanation of (A).

• Both (A) and (R) are true, but (R) is not the correct explanation of (A).

• (A) is true, but (R) is false.

• (A) is false, but (R) is true.

Answer 1

(A) is true, but (R) is false.

Explanation:

In molecular diagnostics, a probe is a single stranded DNA or RNA labelled with a radioactive molecule. Probes detect specific nucleotide sequences associated with genes or pathogens in a sample. A probe does not always find and hybridise with its complementary DNA in a clone of cells. Probes can hybridise with complementary sequences anywhere, not just within clones of cells.