Protista Protozoan Plasmodium

Protista Protozoan Plasmodium 

 INTRODUCTION: In this chapter, Protista Protozoan Plasmodium will discuss in detail. Protozoans were firstly studied by Leeuwenhoek in 1677.

Characteristics features of Protozoan Protists:

• Habitat can be freshwater or marine.
• They are small, acellular, and calcareous.
• Pseudopodia, flagella, and cilia are Locomotory organs.
• Osmoregulation occurs by contractile vacuoles.
• Having radial or bilateral symmetry.
• The mode of nutrition is Holozoic.
• Reproduction occurs asexual or sexual.
• During adverse conditions, they form cysts for survival.
• Ammonia is a metabolic waste.

Classification of Protozoan Protists on basis of Locomotory organelles:

Mastigophora, Sarcodina, Sporozoa, and Ciliata

1. Group: Mastigophora: (Zooflagellate)

• The outer covering is a pellicle.
• Asexual reproduction occurs by Binary fission.
• The locomotory organ is the flagella.
• Association is commensals or symbionts.
• E.g. Trypanosoma gambiense, Leishmania donovani, Giardia intestinalis, etc.

Trypanosoma gambiense: 

• Sleeping sickness parasite.
• Transmit by blood-sucking Glossina palpalis.
• It is present in blood plasma in humans.
• It makes the unconscious.

Leishmania donovani:

• Cause black sickness.
• Also occurs anemia, effects on liver and spleen.
• Transmit by Phlebotomus argentipes.
• It is common in India and America.

Image 1: Zooflagellates

Trichomonas vaginalis: 

• Effects the women's vagina.
• It causes leucorrhoea disease.

Giardia intestinalis:

• Transmission occurs by food and water.
• It affects the part of the small intestine.
• It also causes diarrhea, head pain, epigastric pain, increases body temperature, etc.

2. Group: Sarcodina: (Rhizopoda)

• Locomotion by the Pseudopodia.
• Found in fresh and seawater.
• Nutrition is holozoic.
• Asexual and sexual reproduction takes place.
• E.g. Amoeba proteus, Entamoeba histolytica, Globigerina etc.

Image 2: Amoeba

SEE ALSO: Protista Photosynthetic Dinoflagellates Euglenoids

Amoeba proteus: 

• Locomotion occurs by Lobo podia.
• Osmoregulation occurs by the contractile vacuole.
• Holozoic is the mode of nutrition.
• Contractile vacuole works faster in distilled water.
• Having Mitochondria.

Entamoeba histolytica: 

• The life cycle is monogenetic.
• The disease is known as amoebiasis.
• Contractile vacuole is not present.
• It affects the large intestine and forms ulcers.
• Abdominal pain was also reported.
• It has two forms i.e., Magna and minuta 
• Effective medicine to kill this causal organism is Metragyl or Flagyl.

The life cycle of Entamoeba histolytica

Radiolarians:

• Mostly found in marine.
• For locomotion pseudopodia are present.
• Protoplasm is differentiated.
• Reproduction occurs by binary fission.
• Examples: Acanthometra and Collozoum.

Foraminiferans:

• Found in fresh and marine water.
• For creeping and ingestion pseudopodia are present.
• Reproduction occurs through binary and multiple fission.
• Examples: Globigerina and Elphidium.

Heliozoans:

• Contains axopodia.
• Scales and spines having on the skeleton.
• Example: Actinophrys etc.

3. Group: Sporozoa:

• They are endoparasite.
• Locomotory organelles are not present.
• Contractile vacuoles is not present.
• Sexual reproduction by syngamy.
• The Mode of Nutrition is Parasitic.
• E.g. Plasmodium, Monocystis, Eimeria, etc.

Plasmodium (The Malarial Parasite):

a) Human beings: Inhuman, malarial parasites reproduce asexually.

b) Female Anopheles Mosquito: Malarial parasites reproduce sexually.

A) Life cycle of Plasmodium in Human: Infection occurs by Sporozoite.

• Pre-erythrocytic Schizogony: When sporozoite becomes rounded known as schizont. 

 Schizont → multiply and → form Crypto zoites → moves into sinusoids (in the liver).

• Exo-erythrocytic Schizogony: Crypto zoites → Form Meta cryptozoites.

• Erythrocytic Schizogony: Schizogony in the RBC is known as Erythrocytic Schizogony.

Metacryptozoite → enters RBCs, it follows many steps:

1. Young Trophozoite: When Metacryptozoite moves into RBCs they become round and this stage is known as Young Trophozoite.
2. Amoeboid Stage: When Vacuole is disappeared and these Trophozoites change the shape i.e., amoeba-shaped. Trophozoites acquire hemozoin granules they derived from Erythrocytes. Haemoglobin having protein and iron parts.
3. Formation of Merozoites: Trophozoite perform mitotic division and form merozoites. RBC releases merozoites in human blood and appears symptoms of fever known as the Incubation period. Symptoms of Malaria: Fever, chilliness, headache, muscular pain, etc.
4. Formation of Gametocytes: Some Merozoites form gametocytes, these form Smaller gametocytes and Larger gametocytes.

B) Life Cycle of in the Female Anopheles Mosquito:

• Female Anopheles suck the blood from infected human and gametocytes comes into the lumen of mosquito.
• The formation of gametes is known as Gametogony.
• Formation of Zygote i.e., Fertilization.
• The encyst zygote known as Sporont.
• The nucleus of the oocyte divides and forms small haploid nuclei.

The life cycle of Malarial Parasite

Control of Malaria:

1. Elimination of Mosquitoes: Mosquitoes killed by D.D.T, Flit, etc.
2. Destruction of larvae.
3. Breeding grounds of larva should be drained.

Treatment of Malaria: Antimalarial drug-like Quinine, paludrine, Comoprima, etc.

4. Group: Ciliate: 

• Develop the number of cilia during the life cycle.
• A pellicle is the outer covering of ciliate protozoans.
• They live in fresh and marine water.
• Locomotory organs are cilia.
• The contractile vacuole is present for osmoregulation.
• The mode of nutrition is Holozoic.
• Asexual and sexual reproduction takes place.
• Examples: Paramecium, Balantidium, Vorticella, etc.

Paramecium caudatum:

• Found in freshwater.
• It is a surface feeder.
• The mode of nutrition is microphageal.
• The shape is like a Slipper.
• Outer covering pellicle maintains the shape of the body.
• It having macronucleus and micronucleus.
• It having a contractile vacuole for osmoregulation.
• Transverse binary fission method for asexual reproduction.
• Conjugation and autogamy method for sexual reproduction.

Two types of paramecia:

1. Sensitive Paramecia: Having no kappa particles and do not produce poisonous substances.
2. Killer Paramecia: Having kappa particles and secretes paramecin.

Balantidium coli:

• Found in the large intestine of humans.
• Causes diseases like diarrhea, ulceration, etc.
• Transmission through contaminated water and food.

S.NO.	Parasite	Distribution	Habitat	Disease cause	Transmission
1	Trypanosoma gambiense	Central Africa	Blood, cerebrospinal fluid	Gambium sleeping sickness	By Glossina palpalis
2	Trypanosoma cruzi	South America	Blood	Chagas disease	By Faeces of bugs (triatomid)
3	Leishmania donovani	India	Lymph glands, Liver, Spleen	Kala-azar	By bites of Phlebotomus argentipes
4	Giardia intestinalis	World-wide	Small intestine	Diarrhea	By food and water
5	Trichomonas vaginalis	World-wide	Vagina	Leucorrhoea	Sexual intercourse
6	Entamoeba histolytica	World-wide	Large intestine	Amoebic dysentery	By food and drink
7	Leishmania brasiliensis	Asia and Africa	Nose, Mouth, Pharynx	Mucocutaneous Leishmaniasis	By sandfly

             Table 1: Pathogenic Protozoans in Human being

SEE ALSO: Fungi Phycomycetes Ascomycetes Basidiomycetes

Conclusion: Protozoans in parasitic form affect humans and animals. In this chapter, Protista Protozoan Plasmodium above the information is completed in detail with images.