Difference Between Ova and Cyst

Main Difference – Ova vs Cyst

Ova and cyst are two reproductive structures of parasites found in the stool of the host. Both ova and cyst can be ingested through drinking water and food contaminated with feces of an infected individual. Parasites enter into the gastrointestinal tract of the host animal via the fecal-oral contamination. The life cycle of the worm-like parasites is composed of the eggs/ova, larva, and adult. The parasitic protozoa lifecycle is composed of the trophozoite and the cyst. Both ova and cyst are the propagation stages of parasites. The main difference between ova and cyst is that ova are a life stage of parasitic worms whereas cyst is life stage of parasitic protozoa.

Key Areas Covered

1. What are Ova
     – Definition, Facts, Structure
2. What is a Cyst
     – Definition, Facts, Structure
3. What are the Similarities Between Ova and Cyst
     – Outline of Common Features
4. What is the Difference Between Ova and Cyst
     – Comparison of Key Differences

Key Terms: Cyst, Encystation, Larva, Ova, Parasites, Protozoa, Reproduction, Trophozoite, Worms

Difference Between Ova and Cyst - Comparison Summary

What are Ova

Ova are eggs of parasitic worms that occur in the feces as an indicator of parasitic disorders. Typically, worms lay eggs during reproduction. Some of the worms such as tapeworms and flukes are hermaphrodites while others such as roundworms are unisexual. Different types of ova of parasitic worms are shown in figure 1.

Difference Between Ova and Cyst

Figure 1: Ova Types

Typically, a worm may deposit a thousand of ova daily. The ova consist of a strong shell, protecting them from unfavorable environmental conditions. The shell is made up of three layers: outer proteinic later, middle chitinous layer, and inner lipoidal layer. So, these ova are viable for 1 – 2 months in sewage, soil or fresh water. They can enter into the host through fecal-oral contamination. The larva hatches from viable ova inside the host in most parasitic worms.  

What is a Cyst

A cyst refers to a resistance stage of a protozoan that helps to survive in unfavorable environmental conditions. As the cyst is the propagation stage of the parasitic protozoa, it is infectious. Encystation refers to the process of formation of the cyst. It takes place in the rectum of the host. Therefore, cysts can be identified in the feces. Cysts are spherical structures. They are covered with a hard cyst wall with two layers. The contractile vacuole, macronucleus, and cilia are visible in young cysts. The organelle structures of the old cysts are granular. The metabolism and motility are arrested in cysts. A cyst is shown in figure 2.

Main Difference - Ova vs Cyst

Figure 1: A Cyst

The growing and reproductive stage of the cyst is the trophozoite. The formation of the trophozoite from a cyst is referred to as the excystation. The excystation takes place in the large intestine of the host at the subsequent ingestion of the cyst by the host. Trophozoites are not resistant structures. Generally, trophozoites are covered with cilia. Hence, they are motile. They exhibit rotary or boring motility. They absorb nutrients from the host and reproduce inside it.

Cysts also occur in bacteria and nematodes. In bacteria, cysts are less resistant than spores. They allow the dispersal of bacteria. They germinate in the favorable environmental conditions. The cysts occur in plant-parasitic nematodes as a part of their lifecycle.

Similarities Between Ova and Cyst

  • Both ova and cyst are the propagation stages of parasites.
  • Both ova and cyst can be identified in the stool of infected individuals.
  • Both ova and cyst can be either round, oval, triangular, square or d-shaped.
  • Both ova and cyst are infectious.

Difference Between Ova and Cyst

Definition

Ova: Ova refer to the eggs of parasitic worms that are found in the feces as an indicator of parasitic disorders.

Cyst: A cyst refers to a resistance stage of a protozoan that helps to survive in unfavorable environmental conditions.

Significance

Ova: Ova are the propagation stage of parasitic worms.

Cyst: Cyst is the propagation stage of parasitic protozoa.

Size

Ova: The size of the ova is typically large.

Cyst: The size of the cyst is small.

Thickness of the Wall

Ova: The ova consist of a thick wall.

Cyst: The cyst consists of a thin wall.

Filled with

Ova: The ova are filled with cytoplasm and nucleus.

Cyst: The cyst is filled with fluid, so, it is more fragile.

Conclusion

Ova and cyst are two propagation stages of parasites. Ova are the propagation stage of parasitic worms while cyst is the propagation stage of the parasitic protozoa. Both of them can be found in the stool of the infected individuals. The main difference between ova and cyst is the type of organisms in which each propagation stage occurs.

Reference:

1. “Ova and Parasites (Stool).” Ova and Parasites (Stool) – Health Encyclopedia – University of Rochester Medical Center, .
2. Berkey, The. “Microbial Cysts in Drinking Water – Why Do We Have to Know About It.” The Berkey,

Image Courtesy:

1. “” By SusanA Secretariat Catalina Maya Rendón –  via
2. “Entamoeba histolytica 01″ By Photo Credit:Content Providers(s): CDC/ Dr. George Healy –  Centers for Disease Control and Prevention’s Public Health Image Library (PHIL) (Public Domain) via

About the Author: Lakna

Lakna, a graduate in Molecular Biology & Biochemistry, is a Molecular Biologist and has a broad and keen interest in the discovery of nature related things

Leave a Comment


Related pages


how are the inner planets differentmilk sterilization processdifference between eukaryotic and prokaryotic dnaaustralia constitutional monarchydefinition of unsaturated fatsdifference between lysogenic and lytic cyclewhat is the meaning of fiance and fianceepnp npn transistor differencemalinois german shepherdlevis tagsmacronutrients and micronutrients for plantsmetallic and non metallic propertieswhat is the rutherford gold foil experimentmice laser vs opticallead vs led grammarvernier calliper accuracywhat is a asyndetondiurnal and nocturnal animalsfinite and nonfinite verbs examplesdark romanticism authorstypes of thermoset plasticswhat is the difference between sparkling wine and champagnewondered or wanderedwhat is the difference between friend and acquaintance on facebookwhat is the difference between stoma and stomatasynonym for malapropismthe difference between a typhoon and a hurricanedifference between anorexia nervosa and anorexiainterrogative pronounswhat is the difference between direct and indirect objectsdeclarative and imperative sentencesdistinguish between conduction and convectionwhat is the difference between phagocytes and lymphocyteshow do historians and archaeologists investigate historyagranulocytes definitionalkaline vs alkaliwhat is the difference between connotation and denotationwhat is open and closed syllablescaribou or elkprokaryotic mrnadifference between tem and sem microscopesdamped and undampeddefine inverting amplifierfunction of a noun clausenormative economics examplesliteral and figurative language exampleswhat is the difference between stomach flu and food poisoningendosperm of gymnospermcompare and contrast edgar allan poe and nathaniel hawthornediabetes mellitus diabetes insipidusdifference between hurricane and typhoonsrigidity modulus formulaboxer femalespronunciation and annunciationdefinition valence electronsspices and condiments pdfclay's american systempara dia and ferromagnetic materialsdna rna similarities and differencesdifference between siberian and alaskan huskydistinguish between a substance and a mixturechemical formula of glucose and fructosecushing disease and cushing syndromecomplement vs compliment definitionwhat is the difference between diploid and haploid cellssynapsis occurs in prophaseatp vs adpdefinition condimentsaddition condensation polymerizationdefine deistwhat does epithetexamples of non perennial riversdifferences between monocotyledon and dicotyledon plants