This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2019, Subject name: Pediatrics
An affected male does not have affected children but an affected female always has affected children. Type of inheritance? 
Select and explain. 
A. X linked recessive, B. Autosomal recessive, C. X linked dominant, D. Mitochondrial
D: Mitochondrial
Answer: D: Mitochondrial 
Explanation: Mitochondrial inheritance- an affected female passes disease to all her offspring but the affected male can not. Because mitochondrial dna is present in cytoplasm, the child receives cytoplasm and mitochondria of the mother's ovum. Diseases of mitochondrial inheritance- Kearn sayre syndrome Leber hereditary optic neuropathy MELAS (Mitochondrial encephalopathy, lactic acidosis, stroke like syndrome) MERRF (myoclonic epilepsy with ragged red fibres) NARP ( neuropathy ataxia retinitis pigmentosa) CPEO (Chronic progressive external ophthalmoplegia) Pearson syndrome.