During early civilization, the main source of fresh water was from a river. Nowadays, we have reservoirs and lakes to get fresh water. <span />
Answer:
Eukaryotic cells have a true nucleus, which means the cell's DNA is surrounded by a membrane. Therefore, the nucleus houses the cell's DNA and directs the synthesis of proteins and ribosomes, the cellular organelles responsible for protein synthesis. ... In eukaryotes, chromosomes are linear structures.
Explanation:
The stronger survived and the weaker passed on... Those with a weaker immune system had trouble with sickness and usually ended up passing on but those with strong immune systems were stronger and healthier and lived.
Earths food chain starts with the sun then it goes to producers such as plants that absorbs the sun’s energy to produce their own “food”