A 23-year-old woman develops an allergic reaction after receiving penicillin for streptococcal pharyngitis. Penicillin alone is too small to stimulate an immune response but becomes immunogenic after binding host proteins. Penicillin is best classified as which of the following?

Roundworms belong to what phylum? [a] Leeches belong to what phylum? [b]

For two weeks, you have been treating an 86 year old male with DM with a leg wound caused by hitting a coffee table and resulted in a skin flap tear, where the flap necrosed. You have appropriately prepared the wound bed and the wound is now 100% red granulation tissue.  It measures 4.2 x 3.6 x 0.2 cms.  There is no odor, minimal serous drainage, and no pain.  The patient has no significant comorbidities.  How would you cleanse this wound?

Hardy-Weinberg equilibrium is the highly unlikely situation in which allele frequencies do not change from one generation to the next as long as the 5 assumptions are met. Which of the following is one of the assumptions?

Symbiosis must occur between two individuals of the same species.

A naïve T cell recognizes its antigen on a dendritic cell but fails to receive costimulatory signaling through CD28. What is the most likely outcome?

Goldfish are ectothermic? [f]   In fish, what structure is used for gas exchange? [g]  

A researcher cleaves an antibody with papain, generating two antigen-binding fragments and one crystallizable fragment. Which structural components are found in each antigen-binding fragment?

 A newborn presents with severe recurrent viral, bacterial, and fungal infections. Genetic testing reveals null mutations in both RAG1 and RAG2. Which immunologic process is directly impaired?

A kidney transplant recipient develops acute rejection despite appropriate immunosuppression. Which characteristic of MHC molecules contributes most to graft rejection?