10 most difficult biology riddles A list of ten (out of 65) biology related questions that are the most often answered incorrectly Biology quiz Which species of cannabis contains the most THC?Cannabis Sativa. Some studies indicate that, on average, Cannabis sativa has higher levels of CBD compared to THC than C. indica. The effects of sativa are well known for its cerebral high, while indica is well known for its sedative effects which some prefer for night time use. Both types are used as medical cannabis.very hard 20% Cannabis Indica Cannabis Indica 53%Cannabis SativaCannabis Sativa20%Cannabis RuderalisCannabis Ruderalis10%Cannabis KushCannabis Kush15%Created by: Tschuka. Statistics based on 1886 answers in 3 languages »drugs riddles » Which reptile subgroup is considered extinct?Synapsids were the largest terrestrial vertebrates in the Permian period, 299 to 251 million years ago, although some of the larger pareiasaurs at the end of Permian could match them in size. very hard 21% AnapsidAnapsid14%DiapsidDiapsid22%SynapsidSynapsid21%None of the above are extinctNone of the above are extinct40%Created by: Tschuka. Statistics based on 1089 answers in 2 languages »bones riddles » What mushroom is it?Shaggy parasol. The shaggy parasol is popularly praised as a choice edible mushroom. However, it contains toxins which can cause gastric upsets when eaten raw or undercooked, and some individuals show a strong allergic response even after cooking.very hard 22% parasol mushroomsparasol mushrooms52%Shaggy parasolShaggy parasol22%Browned mushroomsBrowned mushrooms11%Toadstool rusty brownToadstool rusty brown12%Created by: Tschuka. Statistics based on 661 answers in 2 languages »food riddles » Which genetic disease is caused by the dysfunction of the 13 chromosome?Patau syndrome. Trisomy 13, also called Patau syndrome, is a chromosomal condition associated with severe intellectual disability and physical abnormalities in many parts of the body. Individuals with trisomy 13 often have heart defects, brain or spinal cord abnormalities, very small or poorly developed eyes very hard 24% Turner's syndromeTurner's syndrome34%Patau syndromePatau syndrome24%Cystic fibrosisCystic fibrosis28%Klinefelter syndromeKlinefelter syndrome12%Created by: Tschuka. Statistics based on 566 answers in 2 languages »DNA riddles » Which physician discovered that contaminated water was the source of the cholera epidemic in London in 1854?John Snow was an English physician and a leader in the adoption of anaesthesia and medical hygiene. He is considered one of the fathers of modern epidemiology, in part because of his work in tracing the source of a cholera outbreak in Soho, London, in 1854. His findings inspired fundamental changes in the water and waste systems of London, which led to similar changes in other cities, and a significant improvement in general public health around the world. very hard 24% Robert KochRobert Koch26%Alexander FlemingAlexander Fleming30%John SnowJohn Snow24%Thomas HodgkinThomas Hodgkin18%Created by: Tschuka. Statistics based on 2149 answers in 2 languages »London riddles » Which animal doesn't belong to odd-toed ungulates?Rhinoceros. Odd-toed ungulates include the horse, the tapir, and the rhinoceros.very hard 25% hippopotamushippopotamus25%rhinocerosrhinoceros25%camelcamel15%okapiokapi33%Created by: Paweł Kołodziejczyk. Statistics based on 5400 answers in 2 languages »animals riddles » People with Cushing's syndrome have high level of ...Cortisol. Cushing's syndrome is caused by either excessive cortisol-like medication such as prednisone or a tumor that either produces or results in the production of excessive cortisol by the adrenal glands. About two to three people per million are affected each year. It most commonly affects people who are 20 to 50 years of age.Women are affected three times more often than men.very hard 25% lymphocyteslymphocytes21%cortisolcortisol25%oestrogensoestrogens33%aldosteronealdosterone19%Created by: Tschuka. Statistics based on 1631 answers in 3 languages »diseases riddles » Which plant belongs to the cabbage family?Rapeseed (Brassica napus) in the case of one particular group of cultivars, canola), is a bright-yellow flowering member of the family Brassicaceae (mustard or cabbage family), cultivated mainly for its oil-rich seed. It is the third-largest source of vegetable oil in the world. very hard 25% lettucelettuce46%RapeseedRapeseed25%spinachspinach18%sorrelsorrel10%Created by: Tschuka. Statistics based on 2814 answers in 2 languages »agriculture riddles » What cells are responsible for the production of blood thrombocytes?Megakaryocytes . Thrombocytes are a component of blood whose function is to stop bleeding by clumping and clotting blood vessel injuries. Mammalian thrombocytes have no cell nucleus: they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow, and then enter the circulation.very hard 25% monocytesmonocytes38%prolymphocytesprolymphocytes21%megakaryocytes megakaryocytes 25%reticulocytesreticulocytes14%Created by: Ninjai. Statistics based on 1439 answers in 2 languages »medicine riddles » What effect does the botulinum toxin have on the neuromuscular junction?It prevents the release of the acetylcholine . Botulinum toxin is a neurotoxic protein that prevents the release of the neurotransmitter acetylcholine from axon endings at the neuromuscular junction and thus causes flaccid paralysis. Although it is the most acutely lethal toxin known, it is used commercially in medicine, cosmetics and research. very hard 27% it escalates the release of the acetylcholine it escalates the release of the acetylcholine 11%It prevents the release of the acetylcholine It prevents the release of the acetylcholine 27%it blocks the postsynaptic receptorsit blocks the postsynaptic receptors48%it escalates the function of the acetylcholinesteraseit escalates the function of the acetylcholinesterase11%Created by: Ninjai. Statistics based on 1609 answers in 2 languages »science riddles » Play biology quiz and see all the questions.