This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Parasitology Pa 1 (Protozoology), Subject name: Microbiology
Stage of falciparum not seen in Peripheral blood smear is 
Select and explain. 
A. Schizont, B. Gametocyte, C. Ring form, D. Double ring
A: Schizont
Answer: A: Schizont 
Explanation: 1. In P. falciparum infection, the later stages of erythrocytic cycle occur in the capillaries of brain and internal organs. Hence only ring forms are found in peripheral blood by microscopic examination but not late trophozoites and Schizonts. 2. In PBS, all asexual erythrocytic stages, as well as gametocytes can be seen in peripheral blood of P. vivax, P. ovale and P. malariae infections but in P. falciparum infection, only ring form and gametocytes can be seen.