Question

Genes located on mitochondrial DNA

• A. Generally show maternal inheritance
• B. Are always inherited from male parent
• C. Show biparental inheritance
• D. Are not inherited like nuclear genes

Answer 1

The correct option is A Generally show maternal inheritance

The nuclear genes follow the Mendelian biparental genetic inheritance but the genes present in chloroplast and mitochondria follow cytoplasmic inheritance. A biparental inheritance includes Mendelian inheritance where the offspring inherits a maternal and a paternal allele of a gene. Cytoplasmic inheritance is the process of transmission of genes, outside the nucleus, from cytoplasm. The cytoplasmic organelles such as mitochondria and chloroplasts govern these traits. Since, female parent contribute much of cytoplasm to the embryo, the cytoplasmic inheritance is maternally transmitted. The male gamete does not contribute cytoplasm to the zygote; and mitochondria is cytoplasmic organelle therefore, its genome is maternally inherited. Option A is correct answer.