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Molecular Basis of Inheritance MCQs
Class XII Biology
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NCERT Based
•
NEET Practice
📘 Concept Based
📝 Exam Level
🤖 AI Explanations
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668 questions in this chapter
Question 241 of 668
📘 CLASS XII
DNA as an acidic substance present in the nucleus was first identified by _______
Friedrich Miescher identified DNA in 1869 and named it Nuclein.
Question 242 of 668
📘 CLASS XII
Based on X-ray diffraction data, _______ and _______ proposed the Double Helix model.
James Watson and Francis Crick proposed the double helix model in 1953.
Question 243 of 668
📘 CLASS XII
Erwin Chargaff observed that for a double-stranded DNA, the ratio between Adenine and Thymine is _______
Chargaff's rule states A=T and G=C, so the ratio is one.
Question 244 of 668
📘 CLASS XII
The two chains of DNA have _______ polarity.
One strand runs 5'->3' and the other 3'->5'.
Question 245 of 668
📘 CLASS XII
Adenine forms _______ hydrogen bonds with Thymine.
Adenine pairs with Thymine via two hydrogen bonds.
Question 246 of 668
📘 CLASS XII
Guanine is bonded with Cytosine with _______ hydrogen bonds.
Guanine and Cytosine are connected by three hydrogen bonds.
Question 247 of 668
📘 CLASS XII
The pitch of the DNA helix is _______ nm.
The pitch (one complete turn) of the B-DNA helix is 3.4 nm.
Question 248 of 668
📘 CLASS XII
There are roughly _______ base pairs in each turn of the helix.
One turn of the helix contains approximately 10 base pairs.
Question 249 of 668
📘 CLASS XII
The distance between a base pair in a helix is approximately _______ nm.
The rise per base pair is 0.34 nm.
Question 250 of 668
📘 CLASS XII
In DNA, a purine always comes opposite to a _______
Purine pairing with pyrimidine ensures a uniform distance between strands.
