What are the features of DNA replication?

The replication process

• DNA double helix.
• Hydrogen bonds break and helix opens.
• Each strand of DNA acts as a template for synthesis of a new, complementary strand.
• Replication produces two identical DNA double helices, each with one new and one old strand.

What are the main features of DNA?

DNA contains four basic building blocks or ‘bases?’: adenine? (A), cytosine? (C), guanine? (G) and thymine? (T). The order, or sequence, of these bases form the instructions in the genome. DNA is a two-stranded molecule. DNA has a unique ‘double helix’ shape, like a twisted ladder.

What is the main function of DNA replication?

DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Replication is an essential process because, whenever a cell divides, the two new daughter cells must contain the same genetic information, or DNA, as the parent cell.

What are the salient features of a DNA and how it differs from RNA?

There are two differences that distinguish DNA from RNA: (a) RNA contains the sugar ribose, while DNA contains the slightly different sugar deoxyribose (a type of ribose that lacks one oxygen atom), and (b) RNA has the nucleobase uracil while DNA contains thymine.

What feature of DNA replication makes it semi-conservative?

This process is known as semi-conservative replication because two copies of the original DNA molecule are produced, each copy conserving (replicating) the information from one half of the original DNA molecule. Each copy contains one original strand and one newly-synthesized strand.

What are the 4 steps of replication?

• Step 1: Replication Fork Formation. Before DNA can be replicated, the double stranded molecule must be “unzipped” into two single strands.
• Step 2: Primer Binding. The leading strand is the simplest to replicate.
• Step 3: Elongation.
• Step 4: Termination.

What are the salient features of the double helix structure of the DNA Proposedby Watson and cricks *?

Watson and Crick proposed the double helix for structure of DNA. Its features are: (i) It is made of two polynucleotide chains, where the sugar-phosphate constitutes the backbone, and the bases project inside. (ii) The two chains have anti-parallel polarity.

What are the features of DNA Class 12?

The salient features of double helix structure of DNA are as follows:

• There are two polynucleotide chains in a double stranded DNA.
• The backbone is constituted by sugar phosphate.
• The two strands possess anti-parallel polarity, means one chain has polarity 5′-3′ and the other has 3′-5′.

What is the importance of DNA replication to all living organisms?

DNA replication occurs in all living organisms acting as the most essential part for biological inheritance. This is essential for cell division during growth and repair of damaged tissues, while it also ensures that each of the new cells receives its own copy of the DNA.

What are the advantages of DNA replication?

The purpose of DNA replication is to produce two identical copies of a DNA molecule. This is essential for cell division during growth or repair of damaged tissues. DNA replication ensures that each new cell receives its own copy of the DNA.

What is the salient features of RNA?

First, unlike DNA which is generally double-stranded, RNA is a single-stranded molecule in many of its biological roles and has a much shorter chain of nucleotides. Second, while DNA contains deoxyribose, RNA contains ribose sugar (there is no hydroxyl group attached to the pentose ring at the 2′ position in DNA).

Is DNA replication unidirectional or bidirectional?

DNA replication is bidirectional from the origin of replication. To begin DNA replication, unwinding enzymes called DNA helicases cause short segments of the two parent DNA strands to unwind and separate from one another at the origin of replication to form two “Y”-shaped replication forks.

What are the salient features of DNA double helix?

Salient Features of DNA Double-Helix. It consists of two polynucleotide chains where the sugar and phosphate group form the backbone and the nitrogenous bases project inside the helix. The two polynucleotide chains have anti-parallel polarity i.e. if one strand has 5′ → 3′ polarity, the other strand has 3′ → 5′ polarity.

What is the process of DNA replication?

Replication begins with the spotting of this origin followed by the unwinding of the two DNA strands. Unzipping of DNA strands in its entire length is unfeasible due to high energy input. Hence, first, a replication fork is created catalyzed by polymerases enzyme which is an opening in the DNA strand.

Why is the leading strand of DNA the simplest to replicate?

The two sides are therefore replicated with two different processes to accommodate the directional difference. The leading strand is the simplest to replicate. Once the DNA strands have been separated, a short piece of RNA called a primer binds to the 3′ end of the strand.

What is the difference between continuous replication and discontinuous replication?

It is to be noted that elongation is unidirectional i.e. DNA is always polymerized only in the 5′ to 3′ direction. Therefore, in one strand (the template 3 ‘ →5 ‘) it is continuous, hence called continuous replication while on the other strand (the template 5 ‘ →3 ‘) it is discontinuous replication.