The vector mosquito bites a contaminated person and ingests female and male gametocytes of the parasite. Within the insect gut the gametocytes differentiate into gametes and fecundation occurs, forming zygotes. Each plasmodium zygote by mitosis (sporogony) generates numerous infective sporozoites that migrate to the salivary glands of the mosquito. When the mosquito bites a person the sporozoites enter the human circulation and when in the liver they undergo the first asexual reproduction (tissue schizogony), releasing several merozoites into the blood. The merozoites infect red blood cells where the second asexual reproduction of the cycle (erythrocytic schizogony) and the production of many other parasites occur; some of these parasites differentiate into gametocytes. The red blood cells then break (hemolysis), the parasites are released in the blood and the cycle can restart.