Zoology - Molecular Basis of Inheritance Question with Solution | TestHub

ZoologyMolecular Basis of InheritanceStructure of DNAEasy2 minPYQ_2020
ZoologyEasysingle choice

'X' is physiologically and biologically active form of DNA. The pitch of its helix is34 Åwith a distance between two adjacent base pair of about3.4 Å. It shows right-handed coiling. Identify 'X'.

Options:

Answer:
A
Solution:

DNA in the cell is a double-stranded helix of B-form DNA which shows right handed coiling. According to the structure determined by Watson and Crick, the polar sugar-phosphate backbones of each strand form the helical scaffold, while the nitrogenous bases are nearly perpendicular to the helical axis in the interior of the molecule. Each base forms hydrogen bonds with a base from the opposite strand. The diameter of the B-DNA is 20 Angstroms, and the distance between base pairs is~3.4Angstroms. The polarity of the backbones is antiparallel, with one strand running3′→ 5′and the other5′→3′direction.

Stream:NTA_ABHYAS_NEETSubject:ZoologyTopic:Molecular Basis of InheritanceSubtopic:Structure of DNA
⏱ 2mℹ️ Source: PYQ_2020

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