Mitochondria contain DNA, the genes of which encode the synthesis of many proteins necessary for the construction and functioning

Mitochondria contain DNA, the genes of which encode the synthesis of many proteins necessary for the construction and functioning of these organoids. Think about how these extra-nuclear genes will be inherited.

In the majority of organisms studied, mitochondria contain only ring DNA molecules; in some plants, ring molecules are also present at the same time. Genes encoded in mitochondrial DNA belong to a group of plasmagens located outside the nucleus (outside the chromosome). The totality of these factors of heredity, concentrated in the cytoplasm of the cell, is the plasmon of this type of organism (in contrast to the genome). In most multicellular organisms, mitochondrial DNA is inherited through the maternal line. An ovum contains several orders of magnitude more copies of mitochondrial DNA than a sperm. In a sperm, there are usually no more than a dozen mitochondria (in humans – one spirally twisted mitochondria), in the small eggs of a sea urchin – several hundred thousand, and in large frog oocytes – tens of millions. In addition, sperm mitochondria usually degrade after fertilization.