10 most difficult biology riddles A list of ten (out of 56) 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 19% Cannabis Indica Cannabis Indica 54%Cannabis SativaCannabis Sativa19%Cannabis RuderalisCannabis Ruderalis10%Cannabis KushCannabis Kush15%Created by: Tschuka . Statistics based on 1730 answers in 2 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 19% AnapsidAnapsid14%DiapsidDiapsid23%SynapsidSynapsid19%None of the above are extinctNone of the above are extinct42%Created by: Tschuka . Statistics based on 894 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 21% parasol mushroomsparasol mushrooms55%Shaggy parasolShaggy parasol21%Browned mushroomsBrowned mushrooms11%Toadstool rusty brownToadstool rusty brown11%Created by: Tschuka . Statistics based on 555 answers in 2 languages »food 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 22% Robert KochRobert Koch27%Alexander FlemingAlexander Fleming30%John SnowJohn Snow22%Thomas HodgkinThomas Hodgkin18%Created by: Tschuka . Statistics based on 1927 answers in 2 languages »London 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 23% Turner's syndromeTurner's syndrome34%Patau syndromePatau syndrome23%Cystic fibrosisCystic fibrosis29%Klinefelter syndromeKlinefelter syndrome12%Created by: Tschuka . Statistics based on 465 answers in 2 languages »DNA 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 24% lymphocyteslymphocytes21%cortisolcortisol24%oestrogensoestrogens34%aldosteronealdosterone19%Created by: Tschuka . Statistics based on 1410 answers in 2 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 24% lettucelettuce46%RapeseedRapeseed24%spinachspinach17%sorrelsorrel10%Created by: Tschuka . Statistics based on 2652 answers in 2 languages »plants 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% hippopotamushippopotamus26%rhinocerosrhinoceros25%camelcamel15%okapiokapi33%Created by: Paweł Kołodziejczyk. Statistics based on 5211 answers in 2 languages »animals riddles » Which of the plants does not belong to the Asteraceae family?Nasturtium comes from the nasturtium family. The others are asteraceae whose family has about 23.6 thousand species of plants.very hard 25% sunflowersunflower12%camomilecamomile11%lettucelettuce50%nasturtiumnasturtium25%Created by: Tschuka . Statistics based on 1421 answers in 2 languages »flowers riddles » What is special about Synalpheus Pinkfloydi shrimp?Hunting with sound. The shrimp, called also Pink Floyd pistol shrimp, may be found in Pacific waters at Panama coast. The sound of its snapping claw shut reaches 210 decibels (while whales achieve 188 decibels), and can kill passing nearby small fish. It is probably the loadest sound an animal creates. very hard 26% hunting with soundhunting with sound26%fluorescent colorsfluorescent colors50%characteristic breeding dancecharacteristic breeding dance11%sizesize11%Created by: smyru. Statistics based on 444 answers in 2 languages »sea animals riddles » Play biology quiz and see all the questions.