There are certain mechanisms involved in the origin of new genes. Which of the following mechanisms occurs between the genomes of the cell organelles like mitochondria, chloroplasts and the nuclear genomes?

It is referred to the situation in which a gene does not have a vertical origin (that is direct inheritance from parent to offspring) but comes from an unrelated genome. It is recognised that this type of transfer occurs between bacteria, and that it also has taken place between the genomes of the cell organelles like mitochondria, chloroplasts and the nuclear genomes.