Animal Kingdom Test 16

Cysts of E. histolytica contains one to four nuclei. Chromatoid bodies are usually present in young cysts as elongated bars with bluntly rounded ends. Glycogen is usually diffuse, but in young cysts it is often present as a concentrated mass, staining reddish brown with iodine.

The adult trophic form of Entamoeba is known as 'Trophozoite' or 'Magna'. It inhabits anterior part of large intestine, i.e., colon of human beings.It leads a parasitic life and resembles amoeba. Its body is covered by plasmalemma and cytoplasm is differentiated into ectoplasm and endoplasm. There is a single large, broad and blunt pseudopodium formed of ectoplasm. Endoplasm contains single spherical nucleus and food vacuoles. Nucleus has a peripheral crown of chromatin blocks and a centrally located nucleolus. Entamoeba lacks contractile vacuole. Thus, the correct answer is option D.

Infection by Entamoeba histolytica occurs by ingestion of mature cysts in fecally contaminated food, water, or hands.Transmission can also occur through exposure to fecal matter during sexual contact Housefly (in which case not only cysts, but also trophozoites could prove infective).

Entamoeba histolytica is a protozoan parasite responsible for a disease called amoebiasis. It occurs usually in the large intestine and causes internal inflammation. The life cycle of Entamoeba histolytica does not require any intermediate host. Mature cysts (spherical, 1215 m in diameter) are passed in the feces of an infected human. Another human can get infected by ingesting them in fecally contaminated water, food or hands. If the cysts survive the acidic stomach, they transform back into trophozoites in the small intestine. Trophozoites migrate to the large intestine, where they live and multiply by binary fission. Both cysts and trophozoites are sometimes present in the feces. Cysts are usually found in firm stool, whereas trophozoites are found in loose stool. Only cysts can survive longer periods (up to many weeks outside the host) and infect other humans. If trophozoites are ingested, they are killed by the gastric acid of the stomach. Occasionally trophozoites might be transmitted during sexual intercourse. Damage is caused by the lysis of epithelial cells, due in part to the insertion of pore-forming proteins into the membrane of the cell. Neutrophils and non-activated macrophages may also be killed and ingested by the organism, limiting the ability of the immune system to deal with the disease. E. histolytica is also capable of phagocytosing red blood cells. They feed up on erythrocytes, mucosa and submucosa of colon.

Entamoeba coli is a non-pathogenic species of Entamoeba that frequently exists as a commensal parasite in the human gastrointestinal tract.

Entamoeba histolytica is an anaerobic parasitic protozoan that infects the digestive tract of predominantly humans and other primates. Transmission of the parasite occurs when a person ingests food/water that has been contaminated with infected feces. The infection E. histolytica is called Amebiasis (or Amoebiasis).

Cysts of Entamoeba coli are usually spherical but may be elongated and measure 10–35 µm. Mature cysts typically have 8 nuclei but may have as many as 16 or more. Entamoeba coli is the only Entamoeba species found in humans that has more than four nuclei in the cyst stage.

Entamoeba gingivalis is found in 95% of people with gum disease and rarely in people with healthy gums. Cyst formation is not present; therefore transmission is direct from one person to another by kissing, or by sharing eating utensils.

E. histolytica usually resides in the large intestine, and can persist there for months or years and cause an asymptomatic intestinal infection.

Chromatoid bodies have cytoplasm with a single nucleus, rarely up to four; often with ingested red blood cells, sometimes with leukocytes, or bacteria; rich in glycogen; with ribosomes arranged in helices which aggregate to form characteristically shaped elongate bars with rounded ends.

Diarrhea with blood is called dysentery. The most common causes of dysentery are Shigella bacteria or Entamoeba histolytica, a type of parasite. These can cause severe infections that inflame the intestines enough to result in bleeding.

Monocystis is a monogenetic parasite which means its life cycle is completed in a single host that is earthworm. The motile infective stage is a sporozoite which is haploid and enters the sperm morula of earthworm to feed and grow.
Entamoeba histolytica is a monogenetic parasite, as it's life cycle is completed in a single host that is man. All other options are digenetic parasites, as they complete their life cycle in two hosts.

Entamoeba histolytica has between 12 and 16 structures similar to chromosomes. If Entamoeba histolytica were diploid, and therefore each band would consist of two chromosomes. Estimates range from 6 to 14 chromosomes.

When cysts are swallowed they cause infections by excysting (releasing the trophozoite stage) in the digestive tract. ... histolytica, as its name suggests (histo–lytic = tissue destroying), is pathogenic; infection can be asymptomatic or can lead to amoebic dysentery or amoebic liver abscess.

Enzymes are protein molecules in cells which work as catalysts. Enzymes speed up chemical reactions in the body, but do not get used up in the process. Almost all biochemical reactions in living things need enzymes. With an enzyme, chemical reactions go much faster than they would without the enzyme.

Precystic (minuta Form): It is smaller, spherical and non- pathogenic stage. Normally, it lives in the lumen of the intestine and rarely found in tissues. It undergoes encystations and helps in transmission of parasites from one host to other.

There are three stages in the life cycle of the Amoeba, trophozoite, pre-cystic and the cystic stage. Quadrinucleate cysts are eliminated in the faeces of the infected person. Infection with Entamoeba histolytica is acquired by indirect fecal-oral route or by sexual intercourse. The water or food which is contaminated with faeces is responsible for the entry of the cyst in the healthy individual. This cyst is the infective stage in the humans. 

Thus, the correct answer is option A.

Cyst are thick- walled structures produced by Entamoeba. They are resistant to desiccation and other harmful conditions but to a lesser amount.

Amebiasis is a disease caused by the parasite Entamoeba histolytica. Infection occurs as a result of ingestion or contact with parasitical cysts. They are transmitted by the consumption of infected food or water.
So, the correct answer is option C.

Pyorrhoea is aggravated by 'Entamoeba gingivalis'.  
Pyorrhoea is also known as 'Periodontitis'. This is called by protozoan called Entamoeba gingivalis which resides in the oral cavities.

Binary fission, the division of a single entity into two or more parts and the regeneration of those parts to separate entities resembling the original.

E. histolytica dispar cysts are spherical and usually measure 12 to 15 µm (range may be 10 to 20 µm). A mature cyst has 4 nuclei while an immature cyst may contain only 1 to 3 nuclei. Peripheral chromatin is fine, uniform, and evenly distributed.