________ is the irrational and excessive fear of an object, activity, or situation.

A slow-growing, acid-fast bacillus provides the following reactions:

Niacin: no color change Pigment: no pigment when grown in dark or light Nitrate: no color change Urease: no color change Semi-quantitative catalase: 25 mm Arylsulfatase: no color change Pyrazinamidase: pink Tellurite: — black precipitate Which of the following patient history/specimen types was the original source for this organism? A) Skin lesion from a 39-year-old female who owns a tropical fish store B) Sputum from an 18-year-old female illegal alien from Mexico C) Stool from a 44-year-old male with HIV D) Lymph node from a 4-month-old male after receiving the BCG vaccine

Which of the following is unique to an individual, is present on every cell in that person's body, and activates T cells?

A. B cells B. Complements C. Cytokines D. Major histocompatibility complex (MHC) E. Natural killer (NK) cells