Question

You are interested in a single-stranded DNA molecule that contains the following sequence:

5′- ..... GATTGCAT .... -3′
Which molecule can be used as a probe that will hybridize to your sequence of interest?
A) 5′-GATTGCAT-3′
B) 5′-TACGTTAG-3′
C) 5′-CTAACGTA-3′
D) 5′-ATGCAATC-3′

Answer 1

The correct probe for hybridization with the DNA sequence 5'-GATTGCAT-3' is Option D) 5'-ATGCAATC-3', which is complementary and antiparallel to the given sequence, following the base pairing rules where A pairs with T and C pairs with G.

Step-by-step explanation:

The single-stranded DNA molecule in question has the sequence 5'-GATTGCAT-3'. To find a probe that will hybridize to this sequence, we must look for a sequence that is complementary and antiparallel to the given sequence. This means that every adenine (A) in the DNA sequence pairs with a thymine (T) in the probe, and every cytosine (C) pairs with a guanine (G), with the probe running in the opposite 3'-to-5' direction.

Thus, the correct probe that can hybridize with the DNA sequence 5'-GATTGCAT-3' is Option D) 5'-ATGCAATC-3'. Here's how the base pairing works:

DNA: 5'-G-A-T-T-G-C-A-T-3'
Probe: 3'-C-T-A-A-C-G-T-A-5'

• DNA Adenine (A) pairs with Probe Thymine (T)
• DNA Thymine (T) pairs with Probe Adenine (A)
• DNA Guanine (G) pairs with Probe Cytosine (C)
• DNA Cytosine (C) pairs with Probe Guanine (G)

Remembering that sequencing is direction-specific and complementary base pairing is crucial when identifying a hybridization probe.