Cestodes Trivia Quiz

Explanation
Taenisae family includes taenia and echinococcus. The hymenolepidae family contains hymenolepis.

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Each proglottid is hermaphroditic.

Explanation
True - it hatches after the embryonated egg is passed in the faeces. Its movement attracts copepods. Once eaten, they become procercoids. These are then eaten by bigger fish where they become plerocercoids.

Explanation
Diphyllobothrium is commonly known as the fish tapeworm. This parasite primarily infects humans through the consumption of raw or undercooked fish. It is the largest tapeworm that infects humans and can reach lengths of up to 30 feet. The fish tapeworm can cause symptoms such as abdominal pain, diarrhea, and vitamin B12 deficiency. Proper cooking of fish and thorough washing of fruits and vegetables can help prevent the infection.

Explanation
The correct answer states that more proglottids are passed per day for T.solium compared to T.saginata. This means that T.solium sheds a higher number of segments from its body on a daily basis. Additionally, it is mentioned that T.solium has less uterine branches per proglottid than T.saginata, indicating that T.solium has a lower number of branches in its reproductive system. Lastly, the answer states that the scolex of T.solium has four suckers and a crown of hooks, suggesting that the scolex of T.solium has both suckers and hooks.

Explanation
Humans are the only definitive hosts of Taenia solium and saginata because these parasites can only complete their life cycle in the human body. Definitive hosts are organisms in which the adult stage of a parasite resides and reproduces. In the case of Taenia solium and saginata, the adult worms live in the intestines of humans, where they produce eggs that are then excreted in feces. These eggs can infect other intermediate hosts, such as pigs or cows, but only humans can harbor the adult worms. Therefore, it is true that humans are the only definitive hosts for these parasites.

Explanation
Taenia and Echinococcus eggs are morphologically indestinguishable, however Echinococcus eggs are not passed in the faeces of the intermediate host (which can include humans) because the egg hatch in the small inestine and the oncosphere penetrates the gut wall forming cysts. They are, however, passed in the faeces of the definitive host (foxes and dogs).

Taenia eggs however, are passed in the faeces from adult worms in the small intestine in proglottids or on their own if it has disintegrated.

Explanation
Foxes are the definitive hosts for E.multilocularis, and dogs are for E.granulosis.

Granulosis is found worldwide and Multilocularis particularly in Europe, North America, China and Siberia.

Explanation
Diphyllobothrium is a type of tapeworm that can infect humans. It has the ability to absorb vitamin B12 from the host's intestines, leading to a deficiency in this essential nutrient. This can cause symptoms such as anemia, fatigue, and neurological problems. Therefore, the statement that Diphyllobothrium can cause a B12 deficiency is true.

Explanation
Only T.solium can cause cysticercosis.

Explanation
Multilocularis produces an alveolar cystic disease in the liver (alveolar echinococcus) which may spread to other organs. Granulosus produces hydatid disease.

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The cyst filled organs of the intermediate hosts are eaten by the definitive hosts (dogs and foxes). The protoscolices in the cysts are released, they evaginate and attach to the intestine of the definitive host where they produce eggs released in the faeces.

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Bears serve as reservoir hosts for diphyllobothrium, meaning they can harbor and transmit the parasite without showing any symptoms. This is supported by scientific evidence and research, making the statement true.

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The correct answer is 65 - 70 microns. This means that a Diphyllobothrium egg is approximately 65 to 70 microns in size.

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Not feeding dogs the uncooked offal of sheep is a preventative measure for Echinococcus infection. Echinococcus is a genus of tapeworms that can infect both humans and animals. The tapeworm eggs are often found in the intestines of dogs, and when dogs consume uncooked offal of sheep that may contain these eggs, they can become infected. This can then lead to the transmission of the tapeworm to humans through contact with contaminated dog feces or by ingesting food or water contaminated with the eggs. Therefore, by avoiding the feeding of uncooked offal to dogs, the risk of Echinococcus infection can be reduced.

Explanation
They are wider than long. This is also true for hymenolepis.

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Rodents form part of the lifecycle when they (or humans) eat arthropods (beetles and fleas) infected with cysticerci.

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Humans are the only definitive hosts for this worm.

Explanation
Diphyllobothrium is found in Europe, Asia, and the Americas. This indicates that the parasite is widely distributed across these continents. The answer options "Only South America," "Only Africa," and "Only India" are incorrect as they suggest that Diphyllobothrium is restricted to a single continent or country. However, the correct answer suggests a broader geographical range for the presence of this parasite.