NEETZoologyMolecular Basis of Inheritance
What is a gene defined as in genetics?
Options
- AA segment of DNA that codes for tRNA or rRNA
- BA unit of inheritance
- CA segment of DNA that codes for a polypeptide
- DA DNA sequence coding for a mRNA molecule
Correct answer
B. A unit of inheritance
Step-by-step solution
A gene is defined as the functional unit of inheritance. Though there is no ambiguity that the genes are located on the DNA, it is difficult to literally define a gene in terms of DNA sequence. The DNA sequence coding for tRNA or rRNA molecules also defines a gene. However by defining a cistron as a segment of DNA coding for a polypeptide, the structural gene in a transcription unit could be said as monocistronic (mostly in eukaryotes) or polycistronic (mostly in bacteria or prokaryotes). In eukaryotes, the monocis