Answer: The Tigris-Euphrates river system, where Mesopotamia started, was an area prone to frequent flooding. The flooding deposited valuable silt onto the land and enabled crops to be grown and harvested in surplus. This was the first time farmers had an excess of what they needed. The surrounding land was devoid of most other raw materials, such as wood, stone and metal. To get these materials, the early Mesopotamians resorted to trade. At these gathering hubs, people began constructing buildings, which formed the basis for the first cities to appear and helped civilizations continue to develop.
Cloning results in two organisms that are both adult mammals
hope this helps!
Answer:
I think the answer will be c..
The answer here is D, and it's kind of obvious. But you probably already knew the answer and are just doing this for piece of mind.
Explanation: Just the fact that we don't know whether or not there even is extraterrestrial life rules out every other answer, without even needing to go in depth.
(Okay, I read your question completely wrong, it's asking for which one of these has been solved isn't it?)
This is tough because all of these other than D have been figured out. Go with the methane atmosphere then.
Eukaryotic.
In prokaryotic cells, the dna is inside the cytoplasm
