What is the complementary DNA sequence for the DNA strand shown in the figure below?
The Correct Answer and Explanation is :
o determine the complementary DNA sequence for a given DNA strand, we apply the principle of complementary base pairing, where adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G).his means that for each base in the original DNA strand, there is a corresponding complementary base in the new strand.
Steps to Determine the Complementary DNA Sequence:
- Identify the Original DNA Sequence: egin with the DNA strand for which you need to find the complementary sequence.
- Apply Complementary Base Pairing: or each nucleotide in the original strand, write down its complementary base: – pairs with T – pairs with A – pairs with G – pairs with C
- Determine the Directionality: NA strands have directionality, indicated as 5′ to 3′. The complementary strand will be in the opposite direction, 3′ to 5′.
- Write the Complementary Sequence: fter determining the complementary bases and their directionality, write out the new DNA sequence.
Example:
onsider the original DNA strand:
‘ – A T G C C A T G G A T C A T G – 3’
pplying complementary base pairing:
A → T T → A G → C C → G C → G A → T T → A G → C G → C A → T T → A C → G A → T T → A G → C
he complementary DNA strand is:
‘ – T A C G G T A C C T A G T A C – 5’
his complementary strand is antiparallel to the original strand, meaning it runs in the opposite direction (3′ to 5′) and has complementary base pairs.
Understanding Complementary DNA Sequences:
he concept of complementary DNA sequences is fundamental in molecular biology.t underlies processes such as DNA replication, where the DNA double helix unwinds, and each strand serves as a template for the formation of a new complementary strand.his ensures that the genetic information is accurately copied and transmitted during cell division.
dditionally, complementary base pairing is crucial in the formation of the double helix structure of DNA, as described by Watson and Crick.he specific pairing between adenine and thymine, and between cytosine and guanine, allows for the precise replication of genetic material.
n laboratory techniques such as polymerase chain reaction (PCR), understanding complementary DNA sequences is essential for designing primers that will bind specifically to target DNA regions, enabling amplification of specific DNA sequences.
oreover, the principle of complementary base pairing is utilized in various diagnostic tools, including DNA microarrays and DNA sequencing technologies, which rely on the hybridization of complementary DNA strands to detect specific genetic sequences.
n summary, determining the complementary DNA sequence involves applying the rules of base pairing to the original DNA strand, resulting in a new strand that is complementary in both sequence and directionality.his concept is foundational in genetics and molecular biology, facilitating the accurate transmission and analysis of genetic information.