The doctor noted that Bill had no tonsils even though he had never had a tonsillectomy. How do you explain this absence of tonsils, an important diagnostic clue when suspecting XLA?

Herpes virus has the ability to go dormant inside of host cells. Explain why antibodies alone would not be able to resolve such an infection.

Primary lymphoid organs include: Thymus gland Yellow bone marrow Red bone marrow Lymph nodes Lymphatic vessels Spleen Tonsils

You are an emergency room physician. Marcus, a 7-year-old boy, has just presented in the ER complaining that (1) his chest hurts, his heart feels funny, and his ankles and knees hurt. His mother says that he has had a fever for the past 24 hours. (2) Upon physical examination, you notice that his ankles and knees are red and swollen, and examination with a stethoscope reveals unusual palpitations (his heart is fluttering). (3) You immediately order an EKG to check for signs of a heart-attack, a CBC blood draw to check for signs of infection, a throat culture to check for presence of Streptococcus, an X-ray of his legs to check for bone fractures or lesions, and a urine sample to check for bacterial contamination.  You are using the scientific method to diagnose Marcus. Which of the following statement(s) is your puzzling observation?   Statement 1   Statement 2   Statement 3   Statement 1 and 2   Statment 2 and 3