What are the three groups of atoms that make up amino acids called? a. carboxyl group, amino group, side chain b. phosphate, sugar ring, nucleotide base c. hemoglobin, oxygen, iron d. carbon, hydrogen, oxygen

Cathy hypothesized that corn would not grow in mud. to test this hypothesis, she took corn kernels and placed 5 in mud, 3 in soil, and 2 in water. to her surprise, the kernels in the mud grew faster than the kernels in the soil. what error might have caused these unexpected results? a. wrong hypothesis b. not enough variables c. undefined control d. too many variables