Which one of the listed statements best describes the process called chemotaxis?: (A) Abnormal fusion of phagosomes to primary lysosomes, (B) Attachment of chemicals to extracellular material to increase phagocytosis, (C) Dilation of blood vessels by chemotherapeutic drugs, (D) Movement of cells toward a certain site or source
Answer is D. Chemotaxis is the unidirectional migration of cells toward a certain site or source.