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Chargaff Rule MCQ - Practice Questions with Answers

Edited By admin | Updated on Sep 18, 2023 18:34 AM | #NEET

Quick Facts

Chargaff Rule is considered one the most difficult concept.
12 Questions around this concept.

Solve by difficulty

EASY

Which one of the following is not applicable to RNA ?

5' phosphoryl and 3' hydroxyl ends

Heterocyclic nitrogenous bases

Chargaff 's rule

Complementary base pairing

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In sea urchin DNA, which is double stranded, 17% of the bases were shown to be cytosine. The percentages of the other three bases expected to be present in this DNA are :

G17%, A 33%, T 33%

G 8.5%, A 50%, T 24.5%

G 34%, A 24.5%, T 24.5%

G 17%, A 16.5%, T 32.5%

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Concepts Covered - 1

Chargaff Rule

Erwin Chargaff provided the rule for base equivalence that formed the backbone of the proposition of the structure of DNA given by James Watson and Francis Crick.
It states that when the DNA from a particular species is subjected to hydrolysis to release its components of purines and pyrimidines, the following would be observed:
- The total amount of adenine released is equal to the total amount of thymine. Similarly, the total amount of cytosine released is equal to the total amount of guanine.
- The base ratio A/T = 1 and C/G = 1.
- So, A/T = C/G = 1, So, A + G = T + C
Chargaff’s rule allows the determination of percent of all the bases present in the DNA sample if we know the percent of any one of the bases.
The rule does not apply to single-stranded DNA genomes as well as to mitochondrial genome.