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Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 ScienceBIOLOGYMolecular Basis of Inheritance4 Marks
Question

  1. Identify the structure shown above.
  2. Redraw the structure as a replicating fork and label the parts.
  3. Write the source of energy for this replication and list the enzymes involved in this process.
  4. Mention the difference in the synthesis based on the polarity of the two template strands.
✓

Answer

  1. It represents the parental or template DNA strands, showing the replication fork.
  2.  
  1. The deoxyribonucleoside triphosphates provide energy.
  2. DNA dependent DNA polymerase and DNA ligases are the enzymes involved;
  1.  
  1. On the template strand with 3' → 5' polarity, DNA synthesis is continuous, in the 5' → 3' direction.
  2. On the template strand with 5' → 3' polarity, DNA synthesis is discontinuous; DNA strand is synthesised as short segments, also in the 5' → 3' direction and the discontinuously synthesised segments become joined by DNA ligase.

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