USABO Miscellaneous Exam Questions with Correct Answers

USABO Miscellaneous Exam Questions with Correct Answers Ectoderm - Answer-skin nervous system sensory organs cornea, lens adrenal medulla pineal gland epithelial linings of mouth + anus Mesoderm - Answer-notochord (later degenerates) skeletal system muscular system excretory system circulatory system lymphatic system adrenal cortex Endoderm - Answer-epithelial lining of digestive system, respiratory system, urainry system, and reproductive system liver pancreas thymus thyroid gland parathyroid gland Benedict's reagent - Answer-detects reducing sugars (all monosaccharides) negative = blue, positive = orange DIFF FROM FEHLINGS: has copper(II) citrate Lugol's solution - Answer-starch test (iodine) negative = dark red, positive = black Biuret solution - Answer-protein test negative = blue, positive = violet-black copper ions account for color change Sudan IV - Answer-lipid test negative = dark red, positive = reddish-orange Fehling's reagent - Answer-blue alkaline solution used to identify reducing monosaccharides (fructose, glucose) positive = brick red precipitate can differentiate between aldehyde and ketone functional groups DIFF FROM BENEDICTS: copper(II) tartrate Tollens' reagent - Answer-silver mirror test test for sugar aldehydes (ketones produce NO change in colorless solution) positive = silver precipitate plant micronutrients - Answer-chlorine (Cl), copper (Co), boron (Bo), iron (Fe), nickel (Ni), sodium (Na), manganese (Mn), molybdenum, zinc (Zn)