biology-class-12-unit-06-chapter-01-genetics-and-evolution-molecular-basis-of-inheritance-l-1-12-cequcogxhza

<h4 id="successrosalind-franklin--maurice-wilkinssuccess"><Success>Rosalind Franklin & Maurice Wilkins</Success></h4>
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<ul>
<li>In 1951, produced the X-ray crystallography pictures of DNA which Watson and Crick used to determine the structure of double-stranded DNA</li>
</ul>
<p><strong>Watson and Crick</strong></p>
<ul>
<li>Discoverered of the structure of DNA in 1953</li>
</ul>
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<p><img alt="image" src="https://temp-public-img-folder.s3.ap-south-1.amazonaws.com/sathee.prutor.images/subject-images/iitpal/image/biology-class-12-unit-06-chapter-01-genetics-and-evolution-molecular-basis-of-inheritance-l-1_12-cequcogxhza-024-0194.4.jpg"></p>
<p><img alt="image" src="https://temp-public-img-folder.s3.ap-south-1.amazonaws.com/sathee.prutor.images/subject-images/iitpal/image/biology-class-12-unit-06-chapter-01-genetics-and-evolution-molecular-basis-of-inheritance-l-1_12-cequcogxhza-05.jpg"></p>
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<h3 id="successdifferent-forms-of-dnasuccess"><Success>Different forms of DNA</Success></h3>
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<ul>
<li>
<p>B-DNA (Balanced DNA) duplex model proposed by Watson and Crick is right handed spiral</p>
</li>
<li>
<p>Another right handed duplex model is A-DNA (Alternate DNA). Here, a single turn of helix has 11 base pairs</p>
</li>
<li>
<p>C-DNA has 9 base pairs per turn of spiral and right handed</p>
</li>
<li>
<p>D-DNA the number is only 8 base pairs and are also right handed</p>
</li>
<li>
<p>Z-DNA (Zigzag DNA) is left-handed double helix with zigzag back-bone, alternate purine and pyrimidine bases, single turn of 45 A length with 12 base pairs</p>
</li>
</ul>
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<p><img alt="image" src="https://temp-public-img-folder.s3.ap-south-1.amazonaws.com/sathee.prutor.images/subject-images/iitpal/image/biology-class-12-unit-06-chapter-01-genetics-and-evolution-molecular-basis-of-inheritance-l-1_12-cequcogxhza-22.jpg"></p>
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<h3 id="successdifferences-between-dna--rnasuccess-1"><Success>Differences between DNA & RNA</Success></h3>
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<table>
<thead>
<tr>
<th>Feature</th>
<th>RNA</th>
<th>DNA</th>
</tr>
</thead>
<tbody>
<tr>
<td>Structure</td>
<td>Single-stranded (except in some viruses)</td>
<td>Double-stranded (except in few viruses)</td>
</tr>
<tr>
<td>Sugar</td>
<td>Ribose</td>
<td>Deoxyribose</td>
</tr>
<tr>
<td>Bases</td>
<td>Adenine, Guanine, Cytosine, Uracil</td>
<td>Adenine, Guanine, Cytosine, Thymine</td>
</tr>
<tr>
<td>Base Pairing</td>
<td>Adenine pairs with Uracil</td>
<td>Adenine pairs with Thymine</td>
</tr>
</tbody>
</table>
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<p><img alt="image" src="https://temp-public-img-folder.s3.ap-south-1.amazonaws.com/sathee.prutor.images/subject-images/iitpal/image/biology-class-12-unit-06-chapter-01-genetics-and-evolution-molecular-basis-of-inheritance-l-1_12-cequcogxhza-048-1602.0.jpg"></p>
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<h3 id="successdifferences-between-dna--rnasuccess-2"><Success>Differences between DNA & RNA</Success></h3>
<div style='float: left; text-align:left; width:100%; font-size:30px;'>
<table>
<thead>
<tr>
<th>Feature</th>
<th>RNA</th>
<th>DNA</th>
</tr>
</thead>
<tbody>
<tr>
<td>Purine vs Pyrimidine</td>
<td>Purine is not equal to Pyrimidine</td>
<td>Purine is equal to Pyrimidine (Chargaff’s rule)</td>
</tr>
<tr>
<td>Complementary Nucleotides</td>
<td>Form hairpin loops and helical structures</td>
<td>Throughout the length of DNA</td>
</tr>
<tr>
<td>Genetic Material</td>
<td>Present in some viruses</td>
<td>Present in all living organisms</td>
</tr>
<tr>
<td>Length</td>
<td>Short, consisting of only a few thousand nucleotides</td>
<td>Large, consisting of millions of nucleotides</td>
</tr>
</tbody>
</table>
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<p><img alt="image" src="https://temp-public-img-folder.s3.ap-south-1.amazonaws.com/sathee.prutor.images/subject-images/iitpal/image/biology-class-12-unit-06-chapter-01-genetics-and-evolution-molecular-basis-of-inheritance-l-1_12-cequcogxhza-048-1602.0.jpg"></p>
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<h3 id="successlets-answer-these-questionssuccess-2"><Success>Lets answer these questions…</Success></h3>
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<p><strong>Question 3.</strong> If the sequence of one strand of DNA is written as follows -</p>
<p>5’-ATGCATGCATGCATGCATGCATGCATGC-3'</p>
<p><strong>Answer.</strong>  3’- TACGTACGTACGTACGTACGTACGTACG-5'</p>
<p><strong>Question 4.</strong> Which bond exist between</p>
<p>$\quad$ A. Two Nucleotides</p>
<p>$\quad$ B. Two strands of DNA</p>
<p><strong>Answer.</strong></p>
<p>$\quad$ A. Phosphodiester Bond</p>
<p>$\quad$ B. Hydrogen</p>
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<img alt="image" src="https://temp-public-img-folder.s3.ap-south-1.amazonaws.com/sathee.prutor.images/subject-images/iitpal/image/biology-class-12-unit-06-chapter-01-genetics-and-evolution-molecular-basis-of-inheritance-l-1_12-cequcogxhza-29.jpg"></p>
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