Except the nucleus, chloroplasts and mitochondria also have their own DNA.Do they also exist in the form of chromosomes?Do they take part in cell division?If no,why?And are the DNA of these organelles hereditary?
Answers
Chloroplasts and mitochondria also have their own DNA .
Structure:- Just like prokaryotic DNA arranged in circular loose chromosomal form DNA of these semi autonomous organelles also exist in circular form inside the organelles .
Replication:-Mitochondria as it is powerhouse of cell is constantly working in all of the cell cycle so it's replication from old Mitochondria goes through out the cell cycle but it's frequency increases multifold during S phase
So Mitochondrial or chloroplast DNA directly don't take part in cell cycle Because there replication is independent of cell cycle.
Heredity :Genes of Mitochondria & Chloroplasts are of maternal inheritance in majority of sexually reproducing organisms . Because nuclear DNA is formed by fusion of male & female DNA but Mitochondria already present in female gamete Is replicated all along the way .