Question

Extra chromosomal DNA occurs in
A. mitochondria
B. ribosomes
C. nucleus
D. chromosomes

Answer 1

Extrachromosomal DNA (ecDNA) is any DNA that is found off the chromosomes, either inside or outside the core of a cell. Most DNA in an individual genome is found in chromosomes contained in the core. Different types of extrachromosomal DNA exist and serve significant natural functions, for example they can assume a part in illness like ecDNA in cancer.

Complete answer:
In prokaryotes, nonviral extrachromosomal DNA are principally found in plasmids though in eukaryotes, extrachromosomal DNA are basically found in organelles.
Mitochondrial DNA is a fundamental wellspring of this extrachromosomal DNA in eukaryotes.
The way that the organelle contains its own DNA bolsters the theory that mitochondria started as bacterial cells overwhelmed by familial eukaryotic cells.
Extrachromosomal DNA is frequently utilized in examination of replication since they are anything but difficult to recognize and isolate.
In spite of the fact that extrachromosomal round DNA (eccDNA) are found in typical eukaryotic cells, extrachromosomal DNA (ecDNA) are a particular element that have been recognized in the cores of malignant growth cells and have been appeared to convey numerous duplicates of driver oncogenes. ecDNA are viewed as an essential instrument of quality enhancement, bringing about numerous duplicates of driver oncogenes and extremely forceful tumors.

So, the correct answer is "option A".

Note: Extrachromosomal DNA in the cytoplasm has been discovered to be fundamentally unique in relation to atomic DNA. Cytoplasmic DNA is less methylated than DNA found inside the nucleus. It was likewise affirmed that the successions of cytoplasmic DNA were not the same as atomic DNA in a similar creature, indicating that cytoplasmic DNAs are not just parts of atomic DNA. In disease cells, ecDNA has been demonstrated to be primarily isolated from the nucleus.