Answer:
Mitochondria: contain some of the DNA and RNA code necessary for their own function.
Explanation:
Mitochondria are the subcellular organelles responsible for the production of energy in the form of ATP. The most unique characteristic of mitochondria is that they have their own genetic system with all the necessary machinery for their expression, that is, for the synthesis of DNA, RNA and all the proteins it encodes. This second cellular genetic system, despite containing a very small number of genes, is essential for cell life because it encodes 13 proteins that make up the mitochondrial respiratory complexes. For the biogenesis of the mitochondria, the coordinated expression of the two genetic systems, the nuclear and the mitochondrial, is required. Genes are arranged in mitochondrial DNA in a very compact way with tRNAs sandwiched between the genes of the rRNAs and the protein encoders. This gene organization is also reflected in its mode of expression and in the unique characteristics of RNAs. The two strands of mitochondrial DNA are fully transcribed as three polycistronic molecules that are further processed by specific enzymes that cut at the 5 'and 3' ends of the tRNAs to originate the mature rRNAs, mRNAs, and tRNAs. The mitochondria also has its own machinery for the synthesis of the proteins encoded in its genome. Mitochondrial DNA differs from nuclear in a number of characteristics. In particular, the mitochondrial genome is inherited exclusively from the mother who transmits it to all its children. This DNA has a tendency to mutate and fix these mutations in population genetic variants, which is why it is being used to study the phylogeny and structure of populations.
