22.3 Scenario Questions
Use the following information to answer the following questions.
Several years ago, scientists discovered a mutation in zebrafish larvae that prevented the
absorption of lipids from dietary fat. Larvae carrying this mutation died shortly after they
hatched because all cells need fat to carry out their normal functions. More recent studies have
determined that the mutation leading to this disorder occurs in a single gene on chromosome 10.
When a normal gene is inserted into embryos carrying the mutation, these fish are able to process
fats normally when they hatch. To discover more about the gene’s function, researchers
examined and compared cells from normal and mutant fish larvae under a microscope. A major
difference was noticed in the intestinal cells. The Golgi apparatus in the intestinal cells of mutant
larvae is much larger than those of normal larvae. As the Golgi apparatus processes fats and
proteins, the lipids become trapped, resulting in the abnormally large size of the organelle.
1) Assuming that the digestive system of zebrafish works like that of a human, what substance
do zebrafish need to make fats more easily digested by enzymes?
A) chyme
B) bile
C) lipase
D) pepsin
2) Assuming that the digestive system of zebrafish works like that of a human, which portion of
the digestive tract is specialized for absorption of the nutrients?
A) stomach
B) small intestine
C) large intestine
D) pharynx