When scientists study organisms in nature (i. e. outside of the laboratory), carefully controlled experimentation is not always possible. In a case involving mating behavior of birds, data might be gathered by

metamorphism is the change of minerals or geologic texture (distinct arrangement of minerals) in pre-existing rocks (protoliths), without the protolith melting into liquid magma (a solid-state change). the change occurs primarily due to heat, pressure, and the introduction of chemically active fluids. i hoped i !

cells spend most of their time in interphase

the answer

b.) bowling ball