in the nucleolus ribosomes are made.
This allows for humans to breed in the same genes and have the same characteristics as the people in their geographic location for example how Asian people share common characteristics with Asian people. But they differ from European people.
The excessive use of water for irrigation in dry climates, with heavy soils, causes salt accumulation because they are not washed out by rainfall. The practice of waterlogging without adequate drainage has also become a serious cause of soil salinization .
