Would this creation even be conscious? If yeah, what would be the true definition of a soul?
Both modern science and Scholasticism have answers to these questions, though 'conscious' and 'soul' are problematic ones in (post-Marxist) science of course.
A more basic question: is it even life? We don't really consider that somethings capable of replication fail to be alive. Two examples are: 1/ no one believes crystals are alive, yet they do seem capable of a kind of replication and growth. 2/ a harder case is viruses, which in modern science have traditionally been held to be 'not alive' while at the same time showing a kind of host-based reproduction, and having evolutionary processes resulting in a 'quasi species'.
The traditional (both Greek Pagan and Christian) definition of 'alive' is that everything alive (including plants and animals) has some kind of soul, and that the 'faculties' of the human soul include plant like (growth and nutrition and reproduction including sexual), animal like (self-mobility and 'sensitive cognition' down through self-intereested calculation for things like 'hunting'), and human like functions (abstract thought, intellect).
A borderline case would be human or animal tissue growing in a test tube, including of course embryos. In vitro fertilization and subsequent implantation into a 'host mother' followed by live birth is already a fact -- so en-souled matter even for humans has been conceived in a test tube, and it doesn't just 'get its soul' at the moment of implantation (or live birth).
The special thing about these quasi-human embryos is that they are 1/ engendered asexually, so that the 'maternal host' is a female egg and the 'paternal ancestor' in a genetic sense is cloned asexually. 2/ they have 'grown' the SEM (stem-cell embryo model) *past* the point of implantation in the uterine lining, and without benefit of a placenta.
BTW, in some techniques (not sure about the OP), the way this is done is to create a mutant human egg that has CANCER genes inserted into it and turned on, so it will grow stem cells like crazy, in cancer-fashion. Then *possibly* to try to turn those same genes off at some point, so the cell / tissue line stabilizes.
So it is unlikely that it would *ever* develop into a viable human embryo capable of eventual birth, or be suitable for artificial implantation as a 'human clone' into a host mother, as was done famously for other mammals with 'Dolly the sheep'.
Thus, what we have is a colony of stem cells starting off with a cancerous host-mother (the modified human egg that has its nucleus replaced with a post-fertilization stem cell line nucleus and starts to divide as a *normal* cell -- never fertilized) and growing through the 'normal' stages but past the point of viable implantation. It is halfway between an 'artificial clone' like Dolly and a 'normal in vitro fertilization child' -- but has grown beyond the point of being other. Don't forget that 'natural clones' happen all the time -- we call them twins.
So,
I answer the questions as best I can from a Christian, Scholastic perspective:
1. tissue, including stem cells generally and these stem cells in particular, exhibits a kind of life, but is not a living organism. Tissue growing in a vat, which is cells undergoing meiosis and mitosis, is alive in the same sense growing cancer cells artificially for study is alive. The life is not organized into a living entity, so it may be a life but does not possess a soul/life of its own and is not a *new* living organism yet. It is not even clear whether it has or will develop organs or 'cease to function' even in the sense of keeping an organ alive for transplant, much less successful raising of a clone.
If you hack off a human arm, it is still 'alive' for a while though it 'dies' and starts to decay over a period of time, like any human organ separated from its body. It doesn't possess a soul of its own, and will never form a complete organism (new soul). It was 'created' by hacking, not by any living reproductive process. Nor if the person who lost the arm lives have you 'killed a soul' though you have damaged one, and also a damaged human 'donor' of the arm. If you manage to re-attach it to another human being and it becomes a living organ of another living soul you have managed an organ transplant, not created a new organism. Same thing with 'tissue grafts'.
A soul is an living entity that has a body, such as a plant, an animal, or a human.
2. this tissue is not fertilized, but undergoes a process similar to cloning. As above, this means it owes its soul to whichever human baby was sacrificed in the past to create the stem cells that provide the viable nucleus with its full genetic complement (only possible via fertilization).
Cloning a viable human embryo in vitro, with or without subsequent implantation, has not been achieved so we don't know if it is 'possible', though it may be.
3. 'consciousness' is not even in view for this tissue, as it is an 'embryo model' and not even a viable embryo capable of developing into a human organism (or any other kind of organism) by any foreseeable process. Modern science cannot even explain the phenomenon of consciousness, much less define it.
As far as we know, consciousness requires intelligence (at least). Probably there are two kinds -- related to the distinction of sensitive intelligence/cognition and rational intelligence/cognition, which is not an accepted distinction in Modern Science, though important for Christianity.
There is a qualitative difference between rational animals (humans), and irrational beasts (non-human animals). That difference is due to the SPECIAL CREATION of each individual human soul at conception -- a process requiring divine intervention, similar to the creation of the World. Clearly, this can happen in the test tube, as 'in vitro fertilization' results in viable human babies not otherwise different from any other viviparous child. To the best of our knowledge, the fertilization process is REQUIRED to create a full human organism, though we do not know what miracles of creation God may choose to do in the future.
Modern science is committed, variously, to the idea that we are really dead (no soul) and that our apparent consciousness is just an illusion -- 'Man the Machine'. Or more commonly to the halfway position, which is to admit that animals are alive (but that 'soul' is an obsolete 'theory' of what life *is*), and to insist, without any particular evidence for it, that humans are *just* animals and since we evolved from animal life some other animal could evolve to be, implicitly, our equal or superior. Including evolving ourselves to be superior to existing humans -- the real purpose of this line of inquiry in 'progressive Marxism'.