Two answers required. A baby’s lungs are considered mature if the ratio between these two molecules is more than 2-to-1. For 10 points each:
[10h] Name these two compounds. One of these compounds is found in the lipid that surrounds nerve cell axons, and the other is a type of amphiphilic yellow-brown fatty substance found in animal tissue.
ANSWER: sphingomyelin AND lecithin (“LESS-uh-thin”) [accept lecithin–sphingomyelin ratio; prompt on L/S ratio; prompt on partial answers; reject “myelin”]
[10e] The lecithin-sphingomyelin ratio is tested using this substance. This liquid fills the “sac” around a fetus.
ANSWER: amniotic fluid [accept amniotic sac]
[10m] The centesis of amniotic fluid to test genetic material is usually safer than a “chorionic sampling” procedure named for these structures. These structures can atrophy from inflammation due to conditions like celiac disease.
ANSWER: villi [accept microvilli; accept chorionic villus sampling]
<Chicago B, Biology>