AAMC 11 BS Question 109

[kkosp2451]

"Mitochondrial myopathies, diseases often characterized by muscle weakness result from mutations in mitochondrial proteins. One myopathy, MDS, exhibits Mendelian inheritance. Another myopathy, MERRF, exhbits maternal inheritance (males and females inherit the disease from the mother only). The genes that cause MDS and MERRF are most likely located in the:
A) nucleus and the mitochondria, respectively.
B) mitochondria and the nucleus, respectively.
C) nucleus in both cases.
D) mitochondria in both cases."

Correct answer: A
I was under the impression that the mitochondria was entirely separate, had its own separate genome. Therefore, because these are mitochondrial proteins, how are they coded for in the nucleus?

---

Members don't see this ad.

 

[homycraz2]

"MDS, exhibits Mendelian inheritance"

"MERRF, exhbits maternal inheritance "

genes that cause MDS and MERRF

A) nucleus (MDS) and the mitochondria (MERRF), respectively.


Don't worry about what you think you know. Follow what the question or passage tells you.

 

[sazerac]

From Wikipedia: "Mitochondrial genomes have far fewer genes than the bacteria from which they are thought to be descended. Although some genes have been lost altogether, many have been transferred to the nucleus, such as the respiratory complex II protein subunits."

It's a symbiotic relationship. Some nuclear genes get translated into proteins, which move to the mitochondrion where they belong.