Wajeeha Rahman on Nearpeer MDCAT Common Room
AssalamuAlaikum everyone, Sir Hamza mentioned in class that mitochondria are present in eukaryotic cells so contain 70S ribosomes. How is this possible? Since eukaryotic cells have 80S ribosomes, shouldn't mitochondria have 80S too? Can someone please explain this.
Hassan Raza Ghumman · 2026-07-12T16:52:55.545Z
chloroplasts and mitochondria were evolved from prokaryotes so they have similarities
Wajeeha Rahman · 2026-07-12T17:09:27.372Z
Noted Thankyou
Laiba Khurshid · 2026-07-12T16:52:59.875Z
Mitochondria retain 70S ribosomes because of their evolutionary history. According to the widely accepted endosymbiotic theory, ancient eukaryotic cells engulfed free-living, bacteria-like prokaryotes. These engulfed bacteria eventually evolved into mitochondria but retained their original prokaryotic machinery—including their 70S ribosomes and circular DNA
Wajeeha Rahman · 2026-07-12T17:05:21.907Z
very well explained ! Thanku Laiba
Doctor Dua .E.fatima · 2026-07-12T16:53:47.142Z
According to endosymbiont hypothesis, mitochondria is also evolve from prokaryote so it has 70s ribosome or chloroplast has also 70 s due to endosymbiont hypothesis
Wajeeha Rahman · 2026-07-12T17:06:49.214Z
Understood! Thankyou
M Usman · 2026-07-12T16:54:56.224Z
This is explained by endosymbiont theory that large pathogens engulfed self replicating bacteria and Instead of digesting it they stabilized it as host . That is why mitochondria and bacteria have alot of things in common
Wajeeha Rahman · 2026-07-12T17:06:02.787Z
oh okay got it, Thankyou!
shahzaib khan · 2026-07-12T16:52:11.082Z
i just accept this as a exception that's it...
Wajeeha Rahman · 2026-07-12T17:08:26.792Z
haha fair enough..