Question

Can there be DNA replication without cell division?

Answer 1

Hint: DNA stands for deoxyribonucleic acid. The process of forming a copy of the DNA molecule is termed as DNA replication. This is the characteristic feature of DNA. The replication is not found in RNA. Similarly, cells can divide through a number of methods such as mitosis, and meiosis, binary fission, etc. Meiosis is also known as reduction division.

Complete answer:
Yes, there can be DNA replication without cell division. An example of such a condition is called 'Polyteny'. Polyteny can be easily seen in Order Diptera of Class Insecta of Phylum Arthropoda i.e. salivary glands of drosophila.

This phenomenon is described by the following points:
> The biological activity of producing two identical replicas of DNA from one original DNA molecule is called DNA replication. In all living organisms, DNA replication takes place acting as the most important part of biological inheritance.

> There occurs DNA replication lacking cell division. Endomitosis is called the replication of chromosomes in the absence of cell or nuclear division, resulting in several copies inside every cell.

> Endomitosis is of two types:
- Polyteny: In certain organisms to increase the cell volume some specialized cells undergo DNA replication without cell division (endomitosis) forming a giant chromosome. example, polytene chromosome in Drosophila melanogaster.

- Polyploidy: It is an inheritable condition of possessing more than two complete sets of a chromosome. It is commonly found in plants and an animal such as salamanders, leeches, and frogs.

Additional information:
Polytene chromosomes found in Drosophila melanogaster are large chromosomes. They have thousands of DNA strands. They deliver a high level of function in specific tissues like the salivary glands of insects. They are produced due to the repetitive DNA replication in absence of cell division and thus form a giant chromosome.

Note: The parent cell gets separated into two daughter cells throughout cell division. But a repetitive replication of DNA without any cell division would lead to an increase in the volume of the cell nucleus.