<prompt> Which of the following statements best describes a key feature of innate immunity?It improves with repeated exposure to a given antigenIt requires antigen processing for activationIt is not associated with primary immune deficiencyIt includes interaction between pattern recognition receptors on phagocytes and pathogen-associated molecular patterns  <response>: Pathogen-associated molecular patterns, found on invading pathogens, are recognised by pattern recognition receptors on phagocytic cells, allowing phagocytosis and subsequent pathogen destruction. Memory, specificity and the need for antigen processing are features of adaptive immunity. Primary immune deficiencies affecting innate immunity are well recognised. 