Reaction of Planaria to Stimuli
Salt Hot Water Chicken Liver Light
Moved Away Moved Away Moved Toward Moved Away

Juan and Carol were studying invertebrates in biology. They knew that segmented or earth worms preferred a dark, moist habitat. During this lab, they would be investigating the responses of organisms called planaria or Dugesia tigrina. These were simple flatworms that still had a one-way digestive system and a very simple nervous system. Juan and Carol placed the planaria in a petri dish containing cool, distilled water that was partially covered with black paper. They shined a light on the dish. Next, they removed the paper and placed a small amount of chicken liver at one end of the dish. They added a few large salt crystals to the water. Finally, they added drops of hot water to the cool water in the petri dish. Their results can be seen in the data table. According to their experiment, all BUT one conclusion is valid.

Acetic acid  /əˈsiːtɪk/, systematically named  ethanoic acid  /ˌɛθəˈnoʊɪk/, is a colourless liquid  organic compound  with the  chemical formula  ch3cooh (also written as ch3co2h or c2h4o2). when undiluted, it is sometimes called  glacial acetic acid.  vinegar  is no less than 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water. acetic acid has a distinctive sour taste and pungent smell. in addition to household vinegar, it is mainly produced as a precursor to  polyvinyl acetate  and  cellulose acetate. it is classified as a  weak acid  since it only partially  dissociates  in solution, but concentrated acetic acid is corrosive and can attack the skin.acetic acidnamespreferred iupac nameacetic acidsystematic iupac nameethanoic acidother namesvinegar (when dilute); hydrogen acetate; methanecarboxylic acid[1][2]identifierscas number64-19-7  3d model (jsmol)interactive image3dmetb00009 reference506007chebichebi: 15366  chemblchembl539  chemspider171  drugbankdb03166  echa infocard100.000.528ec number200-580-7e numbere260  (preservatives)gmelin reference1380iuphar/bps1058keggd00010  meshacetic+acidpubchem  cid176rtecs numberaf1225000uniiq40q9n063p  un number2789inchiinchi=1s/c2h4o2/c1-2(3)4/h1h3,(h,3,4)  key:   qtbsbxvteameqo-uhfffaoysa-n  smilescc(o)=o