I can asssure you that you are the only person confused by the content of that particular sentence.
DOC, I'm sorry, I want to give you the benefit of the doubt and take the high road in dealing with you, but this assertion is simply a lie. You have been "complaining" (such as it is, rooted in scientific inaccuracy and all) about how "atheists" (meaning anyone who accepts evolutionary theory be they religious or not) supposedly don't know that all life evolved from a "single cell". Perhaps you're more ignorant of biology than I suspected, but you have been given multiple links to the base of the phylogenetic tree which demonstrate that while all eukaryotic life possibly or probably shares a common ancestor with all other eukaryotic life, you ignore in the above statement that your OP tried to conflate eukaryotes, bacteria, procaryotes, and viruses in suggesting that all life evolved from one cell when that's not what evolutionary theory suggests.
Leaving that ignorance on your part aside... again for a moment.. all eukaryotic life, which would include plants and animals coming from a common ancestor is the logical conclusion of common ancestry and evolutionary theory and is entirely consistent with the evidence - but that is not the same thing as your (well, current) suggestion that "all plants and animals evolved from a single primordial cell".
We've given you a number of links with a number of other links you could follow showing how all eukaryotic life is likely decended from a LUCA - which was a eukaryote and at that point had likely integrated a number of organelles from other organisms (single cellular) to give rise to eukaryotic single celled organisms and yet you chose to ignore those evidences and stick with your faulty OP premise or pathetically flawed quote mines of current papers abstracts which actually don't support your flawed premise. The complaint is not about your supposed "points", it's about the fact that you've ignored the 2000+ posts since the OP and the correction of the errors in it that you continue to ignore to this day.
You know, I have to wonder sometimes if you are naturally dense or if this is all a big troll, but, again, please stop with the childish appeals to authority, especially when, as Hokulele and others have demonstrated, you don't really understand the issue they were discussing.
There is evidence, especially in the organelles of eukaryotic cells that there is a connection between bacteria and eukaryotes. There is also evidence that viruses have injected parts of their DNA into eukaryotic cells which as become part of our DNA. This is very different than your assertion that "all life" is evolved from a "single cell". So the answer to your question is yes, not no. Humans do have genetic evidence of having evolved from bacteria and, despite your claims in the OP, anyone with more than a passing familiarity with evolutionary theory realizes and embraces this.
Yes, a eukaryotic cell, and a eukaryotic gamete cell most likely. For anyone who knows anything about evolutionary theory the "chicken and egg" cunondrum is a farce. Eggs existed before chickens by hundreds of millions of years, but more specifically, there was a first common ancestral chicken that existed not only as an ova, but as an oviparous egg before it was born so the answer is - the egg.
Your point?