Question

question 16
1 pts
the purpose of peristalsis is to:
break apart chunks of food and mix it in digestive juices.
propel food forward along the gi tract.
absorb food.
enable swallowing.
question 17
1 pts
which of the following is a disaccharide?
glucose
starch
sucrose
glycogen
question 18
1 pts
the sodium cotransport or coupled transport acts to transport sodium ions and glucose molecules ______ the gi lumen.
passively out of
passively into
actively out of
actively into

Explanation:

Question 16

Peristalsis is the rhythmic contraction and relaxation of muscles in the gastrointestinal (GI) tract. Its main function is to move food along the GI tract. Breaking food into chunks and mixing with juices is segmentation, absorption is done by intestinal cells, and swallowing is a different process (deglutition). So the correct option is the one about propelling food forward.

Disaccharides are sugars made of two monosaccharide units. Glucose is a monosaccharide. Starch and glycogen are polysaccharides (many monosaccharides). Sucrose is made of glucose and fructose, so it's a disaccharide.

Sodium - glucose cotransport in the GI tract (intestinal epithelium) actively transports sodium ions and glucose molecules into the cells from the GI lumen. This is an active transport process (requires energy, uses the sodium gradient) to absorb glucose. Passive transport doesn't require energy, and the direction here is into the cells from the lumen for absorption.

Answer:

B. propel food forward along the GI tract.

Question 17