Base pair,chromosome,DNA strand,and nucleus
Agricultural activities. ...
Exhaust from factories and industries. ...
Mining operations. ...
Indoor air pollution.
You put 1 bean seed in each small pot, fill 25 of the pots with only potting soil, and the remainder with 1/2 potting soil and 1/2 compost. Then you put all of them under an equal amount of grow lights. Put them under at the same time, and take notes every day to see if they grow at the same rate or not. If they do, then it proves this hypothesis is correct. If they don't then the hypothesis is wrong
hope this helps