It should be whatever organ the tissue is making up, for instance, muscle tissue can make the stomach.
Hope this helps!
The big bang is a bit complicated.
Now, Kurzgesagt does an amazing video on this (and yes, I know mods dont like links very much) : https://www.youtube.com/watch?v=wNDGgL73ihY
I will explain as best I can. So, lets assume that the big bang theory actually happened for right now before any debates arise. First of all, we have no clue what even started it. There are so many theories as to why it started and was their a universe before the big bang.
Now, this is the interesting part. Every universe has its own laws. We have four laws or forces in ours that we know of (and then we have quantum physics which completely messes with physics but we wont get into that).
The Force of Gravity
The Strong Force
The Weak Force
The <span>Electromagnetic Force
</span>
We have no clue if there are any other universes and if they are, do they have different properties. If so, chemical bonding could be completely different.
So much could be different.
Now, we know there are also some laws like conservation of energy and law of balance. Balance is what made the universe. Atoms had to find their "mate" lets just say and create chemicals. These chemicals would then go on to bind more and more and create other things over time as the universe was also expanding.
The universe is still expanding (and even accelerating its expansion).
Things must be chemically stable and thats how bonds are formed.
Now, this also kinda opens up "why" and science does not always answer "why". Thats more for religion or philosophy.
Its very interesting and I suggest you look into the video I linked.
Hope this helps