Part III is on malaria parasite in the mosquito. You have the human, and the mosquito. So we shall discuss this parasite in the mosquito. What are the events in the mosquito? By the process of merogony, malaria parasites will grow and they become schizonts. And merozoites. This is the usual thing with this infection. You have a schizont, it has merozoites in it. They will, the infected red blood cell or will bite and these will look for red blood cell. Merozoites cause malaria fever. This process of the life cycle of these parasite in the mosquito is termed sporogony. Malaria parasites grow, and they become gametocytes and sporozoites. How? We shall see it. Sporozoites in the mosquito saliva will initiate malaria infection in the humans. We have jumped a lot of these that happen, before the mosquito can inject it, infective forms of this parasite. We repeat ourselves that malaria gametocytes will arise from very young trophozoites, in the red blood cell, very early sporozoites. Gametocytogony will take anything from eight days or more. In malaria, it is about four days to produce gametocytes. That is to say, I repeat myself, gametocytogony may take eight days in Fewer days in Plasmodium vivax, half of the time to generate gametocytes. The blood meal containing gametocytes, in the red blood cell, will initiate the stage development in the mosquito. In the mosquito gut red blood cells will rupture. It's a very different environment. They will rupture, and the gametocytes will be released from the red blood cell. And things will start happening as we move on. These gametocytes, are either macrogametocytes, which are the female, or the male ones, which are microgametocytes. The microgametocytes undergoes a very, very interesting phenomenon we call exflagellation. It makes flagellates, flagellated organism. It's very important, these are flagellated organisms. They look very much like sperm, they will identify macrogametocytes. Exflagellation will take ten to 15 minutes to complete the process. Exflagellation will give you eight nucleated flagellated bodies essential for fertilization of gametocytes. Exflagellated microgametes will tear free from macrogametocyte, and move actively toward the macrogametes and invade them. Let's repeat that exflagellated microgametes tear free from from macrogametes, they move around, they tear free. And then they're very active really. They are to identify a macrogametocyte whom they will invade. And at that time syngamy takes place for a zygote. This is immotile, the zygote is immotile, it elongates to form the ookinete. The dimensions are given there, 18 micrometer long by 3 to 5 micrometer wide. This is a very interesting body. Ookinete is very active. It will penetrate the mosquito gut. The idea here is to move forward to the salivary glands of the mosquito. Where things will happen, an oocyst will be formed. The ookinete will lodge under the outer limiting membrane of the gut. Here, a cyst wall develops on the ookinete to form the oocyst. What comes next is the sporoblast, which are formed from the oocyst. There is also formation of chromatin dots that will arrange peripherally to the sporoblast. Then we come to really interesting, the sporozoites, which the mosquito injects to a human being to initiate malaria. These sporozoites will arise or do arise from sporoblasts. They break loose. And form an entangled mass of oocyst. One oocyst may contain 10,000 sporozoites, it's a very lively population. This make, makes transmission possible. What happens, sporozoites will invade the mosquito coelom, the body cavity. Then sporozoites are happy to make their way to the 3-lobed salivary gland. They assemble about the cells surrounding the salivary glands. They want to get out from the mosquito to the human being. Sporozoites will invade the lumen of the ducts of salivary gland. These are now ready to be inoculated into humans. When the female mosquito will takes a blood meal. Inoculated sporozoites travel to the liver, and the life cycle continues. This marks the end of part III of malaria parasites in the mosquito. We appreciate your participation. Thank you, and goodbye.