What enables a gene to code for different versions of a trait in different organisms?

Astudent conducts an experiment to determine how the amount of water given to a plant affects it growth what is the dependent variable for this experiment

The observations of hooke and van leeuwenhoek documenting the existence of microscopic cells formed the basis of what important theory? a. the cell theory stating that all living things are composed of cellsb. the theory of spontaneous generation, which held that life forms could arise spontaneouslyc. the theory of chemotherapy, or use of antimicrobials to destroy pathogenic organismsd. the germ theory of disease and causative agents

As the human population grows, what happens to our natural-resource requirements? o they increase o they decrease o they do not change. they go in cycles