The Digestive System: Multiple Choice

Which of the following best describes the pH level inside the human stomach? a. 1 b. 14 c. 7 d. the human stomach does not have pH

(A) 1. The lower the number on the pH scale, the more acidic the environment. The human stomach is very acidic (pepsin thrives in acidity), so its pH will be closer to 1 than 7 or 14.

Which of the following is not a function of the pancreas? a. to churn the food into a smooth paste b. to regulate blood sugar levels c. to produce enzymes that break down carbohydrates, proteins, lipids, and nucleic acids d. to produce sodium bicarbonate to neutralize stomach acid

(A) the pancreas does not come into direct contact with the food being digested, so it cannot physically churn the food into a smooth paste

food moves down the esophagus and through the stomach through which of the following processes? a. the contractions of the muscles smooth muscles known as peristalsis b. gravitational forces c. bile softens food so it can fall into the stomach d. B and C

(A) food moves down the esophagus and through the stomach as the smooth muscles contract (peristalsis). Gravity is not a correct answer because food would move down the esophagus even if you were standing on your head.

Too little water absorption in the large intestine leads to a. diarrhea b. diabetes c. constipation d. all of the above

(A) too little water absorption in the large intestine lead sot diarrhea

What is the churned and chemically digested mixture that leaves the stomach to enter the small intestine called? a. bolus b. villi c. chyme d. gross

(C) chyme

Which of the the following organs plays the biggest role in absorbing the nutrients found in foods we eat? a. mouth b. large intestine c. small intestine d. stomach

(C) the small intestine is the most important in terms of absorbing nutrients the body can use to perform life functions

What kind of acid is produced by stomach glands to optimize chemical digestion? a. sulfuric acid b. hydrofluoric acid c. hydrochloric acid d. B and C

(C) the stomach glands produce hydrochloric acid to optimize chemical digestion

the enzyme amylase serves to: a. break down the bonds of proteins b. break the chemical bonds in starches, forming sugars c. A and B d. process lactose present in dairy products

(B) amylase serves to break the chemical bonds in starches, forming sugars.

another name for food that has been chewed and combined with saliva is: a. booger b. bolus c. chyme d. villi

(B) another name for food that has been chewed and combined with saliva is bolus

What kinds of digestion occur in the stomach? a. only mechanical digestion b. mechanical and chemical digestion c. only chemical digestion d. depends on what kind of food you eat

(B) both mechanical and chemical digestion occur in the stomach. The pepsin and stomach acid aid in chemical digestion, while the stomach muscles churn and mechanically digest the food.

Lipase breaks down: a. complex carbohydrate b. lipids c. starches d. nucleic acids

(B) lipase breaks down lipids

Which of the following is an example of mechanical digestion? a. saliva breaking down starches in the mouth b. chewing food c. bile breaking down lipids d. A and C

(B) mechanical digestion is the breaking down of food into smaller pieces, not a change in the chemical structure of the food particles.

most nutrients from food are absorbed through: a. the esophagus b. the walls of the small intestine c. the pancreas d. the walls of the large intestine

(B) most nutrients from food are absorbed through the walls of the small intestine

Once food has been chewed, it then moves into the: a. stomach b. esophagus c. small intestine d. bolus

(B) once food has been chewed, it then moves into the esophagus, where it travels down into the stomach.

Pepsin works best in which of the following environments: a. basic environment b. acidic environment c. neutral environment d. pepsin works despite what kind of environment it is in

(B) pepsin works best in an acidic environment

The purpose of bile is to: a. churn food into a smooth paste b. break down large, indigestible globs of fat into smaller, more processable globs c. break down large, complex proteins into their essential amino acid form d. B and C

(B) the purpose of bile is to break down large, indigestible globs of fat into smaller, more processable globs.

bile is produced in the _________, but stored in the __________. a. liver, pancreas b. gall bladder, pancreas c. liver, gall bladder d. stomach, gall bladder

(C) bile is produced in the liver, but stored in the gall bladder

nutrients are absorbed through the ___________, which are finger-like projections that line the walls of the small intestine. a. flagella b. cilia c. villi d. duodenum

(C) nutrients are absorbed through the villi, which are finger-like projections that line the walls of the small intestine.

The liver produces which of the following? a. sodium bicarbonate b. amylase c. bile d. A and C

(C) the liver produces bile

the primary function of the large intestine is to remove __________ from the undigested material that is left. a. protein b. amino acids c. water d. carbon dioxide

(C) the primary function of the large intestine is to remove water from the undigested material that is left.

Too much water absorption in the large intestine leads to : a. diabetes b. diarrhea c. constipation d. A and C

(C) too much water absorption in the large intestine leads to constipation

Which of the following is an example of chemical digestion? a. chewing food b. enzymes breaking down food into small molecules the body can use c. saliva breaking down starches in the mouth d. B and C

(D) chewing food is an example of mechanical digestion, which only breaks food down into smaller pieces. Chemical digestion actually breaks food down into simple nutrients the body can use, this can happen with the help of enzymes, which can be found in saliva.

Which of the following is NOT likely to be found in feces? a. water b. insoluble dietary fiber c. bacteria d. complex proteins

(D) complex proteins are unlikely to be found in feces because these nutrients are absorbed into the body as the chyme passes through the small intestine

Select the correct order of the four steps of the digestive system (from start to finish): a. elimination, absorption, ingestions, digestion b. ingestion, absorption, digestion, elimination c. elimination, ingestion, absorption, digestion d. ingestion, digestion, absorption, elimination

(D) ingestion, digestion, absorption, elimination

pepsin is: a. an enzyme found in the stomach b. an enzyme responsible for the break down of proteins into smaller polypeptide fragments c. a protein d. all of the above

(D) pepsin is an enzyme and all enzymes are proteins, so pepsin is by default a protein. Pepsin is found in the stomach and is responsible for the break down of proteins into smaller polypeptide fragments.

Which of the following describes the role of saliva in the digestive system: a. to moisten and lubricate chewed food so it can easily be swallowed b. to begin chemically digesting food with the enzyme amylase c. to absorb the proteins present in foods d. A and B

(D) saliva serves the dual purpose of moisturizing and lubricating (mechanical digestion), while also starting the process of chemical digestion with the amylase enzyme.

The function of the appendix is to: a. help absorb rare proteins that the small intestine cannot absorb b. secrete an enzyme-rich fluid that breaks down chyme c. A and B d. none of the above

(D) the appendix does not play an active/essential role in the present day, human digestive system. People live long and healthy lives full of digestion after having their appendix removed.