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Question
Write the steps involved in the molecular mechanism of DNA recombination with a diagram.
Solution
- Homologous DNA molecules are paired side by side with their duplicated copies of DNAs
- one stand place by the enzyme endonuclease.
- The cut strands cross and join the homologous strands forming the Holliday structure or Holliday junction.
- The Holliday junction migrates away from the original site, a process called branch migration, as a result, the heteroduplex region is formed.
- DNA strands may cut along through the vertical (V) line or horizontal (H) line.
- The vertical cut will result in heteroduplexes with recombinants.
- The horizontal cut will result in heteroduplex with non-recombinants.
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| S. no | Gamete types | Number of progenies |
| 1. | ABC | 349 |
| 2. | Abc | 114 |
| 3. | abC | 124 |
| 4. | AbC | 5 |
| 5. | aBc | 4 |
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