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Question: What is the direction of synthesis of DNA? A. Is \[3'\] to \[5'\] B. Is \[5'\] to \[3'\] C. Va...

What is the direction of synthesis of DNA?
A. Is 3′3' to 5′5'
B. Is 5′5' to 3′3'
C. Varies in eukaryotes
D. Varies in prokaryotes

Explanation

Solution

The natural or artificial generation of deoxyribonucleic acid (DNA) molecules is known as DNA synthesis. DNA is a macromolecule made up of nucleotide units that are linked in a repeating structure by covalent bonds and hydrogen bonds. When these nucleotide units are linked together to produce DNA, it is called DNA synthesis. This can happen artificially (in vitro) or naturally (in vivo).

Complete answer:
Option A: The replication fork's asymmetric nature was discovered in the 19701970: the leading strand continues to develop forever, while the lagging strand is generated by a DNA polymerase using the backstitching technique illustrated. As a result, both strands of DNA are produced when DNA is synthesised in the 5′5' to 3′3' orientation.
So, option A is incorrect.
Option B: The asymmetric character of the replication fork was observed as early as the 19701970: the leading strand develops indefinitely, while the lagging strand is created by a DNA polymerase via the backstitching mechanism shown. As a result, DNA synthesis in the 5′5' to 3′3' orientation produces both strands. Because DNA polymerase needs a free 3′3' OH group to start synthesis, it can only synthesise in one direction, by expanding the 3′3' end of a preexisting nucleotide chain. As a result, DNA polymerase travels in a 3′3' to 5′5' direction along the template strand, whereas the daughter strand is generated in a 5′5' to 3′3' direction.
So, option B is correct.
Option C: Eukaryotic linear chromosomes reproduce through strand separation and complementary base pairing of free deoxyribonucleotides with those on each parent DNA strand, just as prokaryotes. DNA replication in eukaryotic cells is bidirectional, just like it is in prokaryotes.
So, option C is also not correct.
Option D: In the same way as prokaryotes do, eukaryotic linear chromosomes reproduce through strand separation and complementary base pairing of free deoxyribonucleotides with those on each parent DNA strand. DNA replication is bidirectional in eukaryotic cells, just as it is in prokaryotes.
So, option D is incorrect.

Hence, Option B is the correct answer.

Note:
The steps in the replication of DNA:
The first step is to create a replication fork. The double-stranded molecule must be "unzipped" into two single strands before it can be duplicated. Primer Binding is the second step. The first strand is the simplest to replicate. Elongation is the third step. Step four is to put an end to it.