YouTube video (just click the link and it will automatically fast-forward to the right time mark for you which is located at about 1 minute 30 seconds)
Perhaps, this was the beginning of the cell as the unit of life. This cell membrane is thought to be only two large molecules thick. Nevertheless, it created an exterior and an interior and made possible the control of the environment inside the cell. The constant passage of water, nutrients and wastes keep conditions inside steady. These mechanisms allow a simple single-celled organism like amoeba to survive.
I don't understand why she left out the indefinite article that, to the best of my knowledge, absolutely must be there. We are talking about one amoeba, so it really should have been like an amoeba. Is there something I'm missing?
And on top of that, it, of course, grammatically should be keepS conditions inside steady, not keep. Because the subject of the sentence is singular.