Question 1

The journey of a potato chip through our digestive tract would be

Accepted Answer

When we eat a potato chip, it goes through our mouth and into the esophagus, which transports it to the stomach. In the stomach, it is broken down further by stomach acid and enzymes. From there, it passes into the small intestine where nutrients are absorbed. Finally, any waste products pass into the large intestine and then out of the body through the anus. Therefore, the potato chip's journey would be mouth to esophagus to stomach to small intestine to large intestine to anus. Option B best represents this sequence.

Question 2

The enzyme that works well in the acidic environment of the stomach is

Accepted Answer

Pepsin is the enzyme that works well in the acidic environment of the stomach. Trypsin and amylase work better in the alkaline environment of the small intestine. Rennin is an enzyme found in baby mammals that aids in the digestion of milk but is not present in adult humans.

Question 3

The image below is illustrating the

Accepted Answer

The image shows the small intestine, which is lined with villi. Villi are tiny finger-like projections that increase the surface area of the small intestine, allowing for more efficient absorption of nutrients. The large intestine does not have villi or any other structures that increase nutrient absorption. Cilia and flagella are not involved in nutrient absorption.

Question 4

The main function of enzymes in the human digestive tract is to

Accepted Answer

Enzymes are responsible for catalyzing chemical reactions that break specific chemical bonds in food molecules. This process helps to break down complex molecules into smaller ones that can be absorbed by the body.

Question 5

The human liver produces bile, a substance that

Accepted Answer

Bile is produced by the liver and stored in the gallbladder. Its main function is to emulsify fats in the small intestine, allowing them to be more easily digested and absorbed. It does not aid in the absorption of vitamin K, neutralize acids produced by pepsin, or break bonds between amino acids.

Question 6

Consider the parts of the digestive system, particularly the place where water is removed before feces are excreted. Which organ is the mostly likely to be responsible for a bout of diarrhea?

Accepted Answer

The colon is responsible for absorbing water from the feces before it is excreted. In cases of diarrhea, the colon may not be able to absorb enough water, resulting in loose or watery stools. The other organs listed (anus, stomach, esophagus) do not have a direct role in water absorption and therefore are less likely to be responsible for diarrhea.

Question 7

Low levels of vitamin D have been linked to seasonal affective disorder, a condition that leads to depression in the winter. Would you expect dark-skinned people to be more or less prone to seasonal affective disorder?

Accepted Answer

Dark-skinned people have more melanin in their skin, which blocks the UVB rays necessary for the body to produce vitamin D. Therefore, dark-skinned people are more prone to vitamin D deficiency and thus more likely to suffer from seasonal affective disorder.

Question 8

The lower region of the small intestine is structured to create large amounts of surface area so that it can more efficiently

Accepted Answer

The lower region of the small intestine, specifically the ileum, is structured with specialized structures called villi and microvilli. These structures increase the surface area of the small intestine, allowing for more efficient absorption of the chemical building blocks produced by digestion. Enzymes are produced throughout the digestive system, but the specific enzymes responsible for breaking down food depend on the type of molecule being digested. Grinding of food occurs primarily in the mouth and stomach, and waste products are eliminated through the large intestine.

Question 9

The function of the esophagus is to

Accepted Answer

The esophagus is a muscular tube that connects the mouth to the stomach and its main function is to carry food from the mouth to the stomach for digestion. It does not break down food physically or chemically, nor does it prepare undigested material and waste for disposal.

Question 10

Food passing though our digestive tract would contain the fewest nutrients in the

Accepted Answer

The colon is the final section of the digestive tract and is primarily responsible for absorbing water and electrolytes from the remaining waste material. By this stage, most nutrients have already been absorbed in the small intestine, therefore the remaining waste material passing through the colon would contain the fewest nutrients.

Question 11

Which of the following is not secreted by the mammalian pancreas?

Accepted Answer

Pepsin is not secreted by the pancreas, it is actually produced by the chief cells in the stomach. The other options, bicarbonate, trypsin, and chymotrypsin, are all enzymes secreted by the pancreas to aid in digestion.

Question 12

Which of the following steps of digestion does not occur in the mouth?

Accepted Answer

Absorption does not occur in the mouth. Absorption of nutrients occurs in the small intestine.

Question 13

As nutrients move across an intestinal villus, capillaries absorb

Accepted Answer

Capillaries in an intestinal villus absorb amino acids and sugars as they move across the villi, which are small fingerlike projections lining the small intestine. Monoglycerides and fats are absorbed by lacteals, which are lymph vessels in the villi.

Question 14

The liver secretes bile to the

Accepted Answer

The answer of The liver secretes bile to the
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Question 15

The gallbladder

Accepted Answer

The gallbladder stores bile, which is produced by the liver and aids in the digestion and absorption of fats.

Question 16

Which of the following does not occur in the colon?

Accepted Answer

The breakdown of fats and carbohydrates primarily occurs in the small intestine, not the colon. The colon's main roles include absorbing water, electrolytes and some vitamins, and eliminating waste materials from the body. Some bacterial fermentation occurs in the colon, leading to the production of some vitamins, but this is not the primary function of the colon.

Question 17

Which of the following would not be found in the lower small intestine?

Accepted Answer

The lower small intestine, also known as the ileum, does not have a low pH. The pH of the small intestine becomes increasingly basic as it progresses from the duodenum to the ileum due to the release of bicarbonate ions from the pancreas and the small intestine. The brush border, villi, and large surface area are all found in the lower small intestine and are important for nutrient absorption.

Question 18

The first enzymes that food encounters in our body are in our

Accepted Answer

The first enzymes that food encounters in our body are in our mouth, specifically in our saliva. Salivary glands secrete enzymes such as amylase, which helps break down carbohydrates in the mouth before the food even reaches the esophagus.

Question 19

How rapidly an organism can absorb nutrients generally depends on

Accepted Answer

The surface area available for absorption plays a significant role in how rapidly an organism can absorb nutrients. A larger surface area means more absorption sites, resulting in faster nutrient uptake.

Question 20

Lipases help digest

Accepted Answer

Lipases are enzymes that help break down fats into smaller components, such as fatty acids and glycerol, so that they can be absorbed and utilized by the body. Therefore, the best choice is D - lipases help digest fats.

Quiz 27: Nutrition and Digestion