What are three attributes of mitochondria and chloroplasts that suggest they were once free-living bacteria?

Video transcript

Hello everyone. Let's look at our next question. The mitochondria and chloroplasts may once have been free living bacteria based on all of the following attributes. Except so this question we can recall from our content video calls to the idea of when we think about the possible evolution of eukaryotic cells and when we look at the presence of mitochondria and chloroplasts inside those cells. And the theory is that mitochondria chloroplasts were originally pro periodic cells that were absorbed into the precursors of eukaryotes and where they formed a mutually beneficial relationship them providing a new energy source for the cells that were absorbed by while receiving shelter and beneficial environment from the cells that absorb them. So what is the evidence that this may have been the case? Well we're going to look at our answer choices and we're looking there are three that are possible clues to this idea and one is not contributing evidence to this theory. So let's look for our exception here. So Choice A. Says circular chromosomes. And yes I'm gonna put a little check mark here. The mitochondria and chloroplasts do have a singular circular chromosome which is similar to the circular chromosome. In pro carry outs they have their own D. N. A. In that circular chromosome separate from the DNA of the eukaryotic cell that they're within. So that obviously would be a strong case for them once having been having been free living bacteria. So not our answer choice B says production of their own ribosomes again. That would be another piece of evidence towards their once having been independent. They make their own ribosomes separate from the ribosomes of the cell that they dwell within. So, Choice B is not our answer. Choice C says same genome length. Well, this is not true. The mitochondria and chloroplasts just have this singular circular chromosome much less DNA than the eukaryotic cell they live within. So, Choice C. Would be the exception as not being evidence based evidence towards the mitochondria and chloroplasts once having been independent cells. And finally, Choice D. Says the division is independent of eukaryotic cellular division. And yes, this is true mitochondria chloroplasts reproduce themselves with him so independently of the cell division and replication of the eukaryotic cell that they are within. So again, another key to another clue to the idea that they once were independent. So mitochondria chloroplasts may once have been free living bacteria based on all the following attributes except Choice C. Same genome length. Thanks for watching. See you in the next video