Answer:
Amount of food. She needs to varry the amount of plant food among the different groups so that she can tell how the amount of plant food affects number of beans produced.
Decomposers are organisms that break down dead organisms and release nitrogen back into the cycle
Multiple alleles. As different blood types can be determined by 2 different alleles
Answer:
It uses fewer land and water resources.
Hope it's right and will help you. Thank you
