00:01
Which of these are ocariotic organelles that definitely arose from endosymbiosis? and we have five options here.
00:10
Okay, so definitely is a strong word, but there is endosymbiotic theory, which has a lot of backing.
00:16
And it's the idea that far back in evolutionary history, billions of years, an ocariotic cell, engulfed a bacterial cell, and instead of digesting it, breaking it down, kept it around.
00:29
Probably my mistake.
00:30
But what you had was a symbiotic relationship between an ocariotic protist, because it was single -cellularity didn't develop until after we got the first of these organelles, and a bacterium.
00:48
And the first time this happened, this bacterium performed aerobic respiration.
00:53
So the relationship was the bacteria get a safe environment with nutrition, and the protist gets the atp for the bacteria.
01:01
Is making.
01:03
And this gave rise to mitochondria.
01:06
So mitochondria.
01:08
Then the second time, and this has happened a few times, it was the engulfing of a photosynthetic bacterium.
01:16
So it kept performing photosynthesis and provided energy molecules like glucose to the host.
01:23
And those became chloroplasts and other plastids as well...