Q: Which of the following equations best represents the ratio of microbial cells to human cells in the body?

$$\text{Microbial cells} : \text{Human cells} = 10 : 1$$

Question 1

Which of the following best describes the main structural difference between Gram-positive and Gram-negative bacteria?

Accepted Answer

Gram-negative bacteria possess an extra outer membrane outside the cell wall.

Question 2

A patient presents with a severe sore throat. A rapid test identifies the infection as viral. Why should antibiotics NOT be prescribed in this case?

Accepted Answer

Antibiotics are ineffective against viruses and their misuse can contribute to antibiotic resistance.

Question 3

Which of the following is NOT a component of the innate (non-specific) immune system?

Accepted Answer

B-lymphocytes

Question 4

A virus must enter a host cell to reproduce. Which of the following best explains why viruses are not considered 'living' organisms?

Accepted Answer

They cannot metabolize nutrients independently.

Question 5

Which of the following equations best represents the ratio of microbial cells to human cells in the body?

Accepted Answer

$$	ext{Microbial cells} : 	ext{Human cells} = 10 : 1$$

Question 6

Which of the following best describes a parasite?

Accepted Answer

An organism that lives on or in a host and obtains food at the host's expense.

Question 7

A patient with COVID-19 develops a secondary bacterial pneumonia. Why might antibiotics be prescribed in this scenario?

Accepted Answer

To treat the associated bacterial infection that developed after the viral infection.

Question 8

Which of the following is a function of B-lymphocytes in the adaptive immune system?

Accepted Answer

Production of antibodies specific to antigens.

Question 9

Which of the following best explains why molecular diagnostic tools are important in distinguishing between bacterial and viral infections?

Accepted Answer

They allow for rapid and accurate identification, ensuring appropriate treatment and reducing unnecessary antibiotic use.

Question 10

Which of the following is an example of a specific (adaptive) immune response?

Accepted Answer

The production of memory cells after vaccination.

Question 11

A scientist is studying a microorganism that contains ribosomes, a cell wall, and free-floating DNA, but no nucleus. What type of organism is this most likely to be?

Accepted Answer

Bacterium

Question 12

Which of the following best describes the role of antigens in the immune response?

Accepted Answer

They are molecules that stimulate an immune response.

Question 13

Which of the following is a common misconception about viruses?

Accepted Answer

Viruses can be killed by antibiotics.

Question 14

Which of the following best explains why the immune system is described as 'adaptive'?

Accepted Answer

It adapts, refines, and strengthens its response upon repeated exposure to the same antigen.

Question 15

Which of the following is NOT a class of human parasites?

Accepted Answer

Bacteria

Question 16

A patient is infected with a bacterium that communicates with other bacteria by releasing chemical signaling molecules. What is the significance of this communication?

Accepted Answer

It allows bacteria to coordinate gene expression and behave as a multicellular organism.

Question 17

Which of the following best describes the process by which bacteria replicate?

Accepted Answer

Binary fission (a form of mitosis)

Question 18

Which of the following is a real-world example of the importance of distinguishing between bacterial and viral infections?

Accepted Answer

Using rapid molecular tests to avoid unnecessary antibiotic use in viral infections.

Question 19

Which of the following is a function of T-lymphocytes in the immune system?

Accepted Answer

Destruction of infected host cells.

Question 20

Which of the following best describes the relationship between viral and bacterial infections in severe pneumonia cases?

Accepted Answer

Bacterial infections can develop as a complication of severe viral infections.

Introduction to Microbiology: Bacteria, Viruses, Parasites, and Immunity

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