Recording-2025-03-13T16:49:03.127Z

Asexual Reproduction: Schizogony

• Definition: A type of asexual division that rapidly generates new life cycle forms.

• Merozoites: The next life cycle form produced during schizogony.

• Invasion of Liver Cells: Released merozoites invade other liver cells.

Erythrocytic Cycle

• Entry into Bloodstream: Merozoites enter the host's bloodstream and invade erythrocytes (red blood cells).

• Transformation into Trophozoite:

  • Once inside an erythrocyte, the merozoite enlarges into a ring trophozoite (uninucleate cell).

• Development of Schizont:

  • The trophozoite's nucleus divides asexually, producing a schizont containing multiple nuclei.

Release of Merozoites

• Division of Schizont: The schizont divides, producing mononucleated merozoites.

• Erythrocyte Rupture:

  • The erythrocyte ruptures, releasing toxins into the host:

    • This leads to the characteristic fever and chills associated with malaria.

Sexual Phase: Gametocytes

• Formation of Gametocytes: Some merozoites develop into gametocytes within erythrocytes that do not rupture.

• Gametocytes: Cells capable of producing male and female gametes, but cannot produce gametes within the human host.

• Mosquito Transmission:

  • Gametocytes are only capable of producing gametes when extracted by a mosquito.

Development within Mosquito

• Gametocyte Formation: In the mosquito's gut, gametocytes differentiate into male and female gametes.

• Zygote Formation: The gametes combine to form a diploid zygote within the intestinal walls of the mosquito.

• Oocyst Development:

  • The zygotes develop into oocysts within the mosquito.

• Mitotic Divisions:

  • Oocysts undergo repeated mitotic divisions, producing numerous sporozoites.

• Migration to Salivary Glands: Sporozoites migrate to the mosquito's salivary glands.

Transmission to Humans

• Infection Cycle Resumes: Sporozoites are injected into the bloodstream of a human by a mosquito, restarting the life cycle of the malaria parasite.