Extranuclear inheritance
- 1. Copyright © 2009 Pearson Education, Inc. Extranuclear Inheritance S.KEERTHANAN BS-1121
- 2. Copyright © 2009 Pearson Education, Inc. What is Extranuclear inheritance? • Extranuclear genes are found in cellular organelles out of nucleus such as mitochondria and chloroplasts. • Via the Extranuclear genes, the characters are inherited to next generation. • It is known as cytoplasmic inheritance or extrachromosomal inheritance.
- 3. Copyright © 2009 Pearson Education, Inc. How was cytoplasmic inheritance discovered? C. CORRENS (1909) and E. BAUR (1909, 1910) described crossings, for which the Mendelian laws did not apply.
- 4. Copyright © 2009 Pearson Education, Inc. C. CORRENS experiment…
- 5. Copyright © 2009 Pearson Education, Inc. • Two types of pollen(white and green pollen) that were used to fertilize the flowers: • Branches with white leaves gave only white leaf progeny. • Branches with green leaves gave only green progeny. • Branches with variegated leaves gave green, white and variegated progeny.
- 6. Copyright © 2009 Pearson Education, Inc. conclusion • Phenotype does not depend on nuclear genotype (pollen not involved) • Must be dependent on cytoplasm of female organs in the flower. • Cytoplasmic inheritance.
- 7. Copyright © 2009 Pearson Education, Inc. Leaf variegation Caused by segregation of different types of chloroplasts
- 8. Copyright © 2009 Pearson Education, Inc. Types of Extranuclear inheritance. • Maternal inheritance : The cytoplasmic organelles such mitochondria & chloroplast are inherited with the egg cytoplasm from the maternal parent. Examples.... • Shell coiling in snail. • Variegation in leaves of 4 o’ clock plant.
- 9. Copyright © 2009 Pearson Education, Inc. Shell coiling in snail.
- 10. Copyright © 2009 Pearson Education, Inc. Types of Extranuclear inheritance.
- 11. Copyright © 2009 Pearson Education, Inc. Thank you… The End
Editor's Notes
- #8: Fig 19.2 Leaf variegation caused by the segregation of different types of chloroplasts.