0

Guest

Courses New
  • Forum
  • AIPMT
  • Length of DNA molecule 170 A 0 . If adenine...

Length of DNA molecule 1700A. If adenine = 20. The number of 2Hbonds are A) 60 B) 30 C) 100 D) 130

Length of DNA molecule 1700A. If adenine = 20. The number of 2Hbonds are
A)  60   B)  30  C)  100  D)  130

Grade:12

2 Answers

Arun
25758 Points
2 years ago
Length of a base pair is 3.4 Å. Hence a DNA segment of length 170 Å has 170/3.4 = 50 base pairs.
It is given in question that 20% of DNA is cytosine. Cytosine forms triple hydrogen bond with guanine resulting in a base pair Hence, an equal percentage ( 20% ) of guanine is present too. Based on this it concluded that 40% of base pairs ( 50×40% = 20 base pairs ) are cytosine-guanine. Each of them has triple bond hence 20×3 = 60 hydrogen bonds.
While rest, 60% ( 50×60% = 30 base pairs ) are adenine-thymine. Each of them has a double bond hence 30×2 = 60 hydrogen bonds. 
 
Hence this dsDNA segment has 60+60 = 120 hydrogen bonds.
Vikas TU
14149 Points
2 years ago
In three turns there will be 30 base pairs of DNA or 60 nucleotides. So, 12 nucleotides are thymine. thymine is double bonded with hydrogen bonds with adenine so 12 nucleotides are adenine according to Chargaff's rule. So it will have 24 hydrogen bonds

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

Other Related Questions on AIPMT

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More