The members of Phylum Ciliophora process of locomotion is carried out by means of short hair-like projections called cilia. Their synchronous beating propels the organism.
Balantidium coli causes balantidiasis. Balantidium exists in two forms: a vegetative trophozoite and a cyst. They are characterized by having two nuclei: a large macronucleus for growth and metabolism and a small micronucleus for cell division.
The cyst form is ingested in contaminated food and water and develops into trophozoites in the large intestine. The large intestines become ulcerated and periods of alternating diarrhea and constipation result.
The members of the Phylum Mastigophora accomplish locomotion by using one or more long whip-like, thin structures called flagella.
The Mastigophorans known as the Trypanosoma are the causative agents of African Sleeping Sickness and American trypanosomiasis.
They live in the bloodstream and progressive symptoms include headaches, fever, and anemia. Pronounced fatigue is experienced and most of the time is spent sleeping until death.
Unlike other members of Protozoa, Sporozoa do not have structures for locomotion in their mature stages, however, immature forms have some type of movement. All the members of this group are parasites.
The most significant is the genus Plasmodium that causes malaria. They are sporozoan parasites with a complex life cycle, part of which is in various vertebrate tissues, while the other part involves parasites. The sporozoites of the organisms are transferred to a human by the bite of a female Anopheles mosquito. The sporozoites enter the bloodstream and migrate to the liver, where they enter the liver cells and transform into merozoites.
Merozoites are released from liver cells and infect erythrocytes, where they undergo asexual reproduction involving sexual stages. The first is called the ring stage, and the second involves the development of schizonts. When mature, the schizont contains a number of merozoites and they are released by lysis from the erythrocytes. The lysis of the schizonts and erythrocytes at once produce symptoms of malaria: chills, which is followed by fever, headache, sweating, and malaise. Released merozoites infect new erythrocytes and repeat the cycle. The cycle of attack is 48 to 72 hours depending on the species.
The sexual phase of the life cycle begins when the merozoites enter the erythrocytes and differentiate into male and female gametocytes. When ingested by the female mosquito during a blood meal, fertilization occurs and the zygote develops into a cyst within the mosquito’s gut wall. After many divisions, the cyst releases, sporozoites, some of which enter the mosquito’s salivary glands ready to be transmitted back to the human.
