From time to time, some merozoites form gametocytes. These can be taken up by a mosquito with a blood meal. Malarial parasites mature into sporozoites in the salivary glands of a mosquito and enter a human when the mosquito bites. Sporozoites invade liver cells and reproduce asexually many times, forming large numbers of merozoites. The infected liver cells burst, releasing merozoites.
Merozoites invade red blood cells and continue to reproduce asexually.
Each red blood cell produces an average of 16 to 20 merozoites. Occasionally 32 merozoites are seen. This is because the red blood cell was originally infected with two parasites. Infected red blood cells rupture and release the parasites and the toxins that cause fever and chills. Some of the parasites are able to form gametocytes .