Q: Which equation best represents the process by which mutualistic bacteria in the rumen of cows convert cellulose into absorbable nutrients?

$$\text{(Cellulose)} + \text{H}_2\text{O} \xrightarrow{\text{bacterial enzymes}} \text{Simple sugars} + \text{Fatty acids}$$

Question 1

Which of the following best explains why herbivores, such as koalas, have longer alimentary canals relative to their body size compared to carnivores like lions?

Accepted Answer

Herbivores need more time and surface area to digest cellulose-rich plant material, which is more difficult to break down than meat.

Question 2

A researcher finds that a mammal has sharp canines and molars with flat surfaces. Based on these dental adaptations, what is the most likely diet of this animal?

Accepted Answer

Omnivorous, as it is adapted for both tearing meat and grinding plant material.

Question 3

Which mutualistic adaptation allows ruminants like cows to efficiently extract nutrients from cellulose-rich grass?

Accepted Answer

Hosting symbiotic microorganisms in a multi-chambered stomach that ferment cellulose.

Question 4

Why is coprophagy (eating feces) an important adaptation for some herbivorous mammals such as rabbits?

Accepted Answer

It allows them to recover nutrients produced by bacterial fermentation in the large intestine, which would otherwise be lost.

Question 5

Which of the following best describes the effect of Helicobacter pylori infection on the stomach microbiome, as shown in the provided data?

Accepted Answer

It dramatically reduces the diversity of bacterial species, with over 95% of bacteria belonging to Proteobacteria.

Question 6

Which equation best represents the process by which mutualistic bacteria in the rumen of cows convert cellulose into absorbable nutrients?

Accepted Answer

$$	ext{(Cellulose)} + 	ext{H}_2	ext{O} \xrightarrow{	ext{bacterial enzymes}} 	ext{Simple sugars} + 	ext{Fatty acids}$$

Question 7

A patient develops severe diarrhea after antibiotic treatment. Which therapy, based on recent microbiome research, is most likely to restore their gut health?

Accepted Answer

Fecal microbial transplantation from a healthy donor.

Question 8

Why do carnivorous vertebrates, such as lions, typically have large, expandable stomachs?

Accepted Answer

To allow them to consume large meals infrequently, storing food until it can be digested.

Question 9

Which of the following is a likely reason why the microbiome composition differs between the stomach and the intestine, even though they are directly connected?

Accepted Answer

The stomach's acidic environment selects for acid-tolerant bacteria, while the intestine supports a more diverse community.

Question 10

Which of the following best explains why eating yogurt containing lactase-producing bacteria provides only temporary relief for lactose-intolerant individuals?

Accepted Answer

The bacteria do not permanently colonize the gut, so their lactase production is short-lived.

Question 11

Which of the following is a real-world application of bacteriophage therapy, as described in the study materials?

Accepted Answer

Using engineered viruses to target and kill multidrug-resistant bacterial pathogens in humans.

Question 12

Which adaptation is found in the digestive system of the hoatzin, an herbivorous bird, to aid in cellulose digestion?

Accepted Answer

A large, muscular crop housing symbiotic microorganisms.

Question 13

What is the primary benefit for humans of hosting mutualistic bacteria in the digestive tract?

Accepted Answer

The bacteria produce essential vitamins and help regulate immune function.

Question 14

Which of the following best describes the nutritional strategy of giant tubeworms living near hydrothermal vents?

Accepted Answer

They rely entirely on mutualistic bacteria that perform chemoautotrophy to obtain energy and nutrients.

Question 15

Which of the following is a plausible explanation for why antibiotic treatment can lead to Clostridium difficile infections?

Accepted Answer

Antibiotics kill resident gut microbiota, allowing C. difficile to proliferate without competition.

Question 16

Which of the following statements about the human gut microbiome is supported by the data on its variation with age and health status?

Accepted Answer

The composition of the gut microbiome changes significantly with age, diet, and health conditions.

Evolutionary Adaptations of Vertebrate Digestive Systems and Their Correlation with Diet

Study Guide - Practice Questions

Study Guide - Flashcards