Question 1

Which of the following types of cells would a flu virus most likely target as the means of entry into the body?

Accepted Answer

Flu viruses typically target epithelial cells lining the respiratory system because these cells provide a direct route for the virus to enter and infect the body, given the flu's transmission through respiratory droplets.

Question 2

Which of the following best describes how the flu virus may impact the respiratory system?

Accepted Answer

The answer of Which of the following best describes how...

Question 3

The most common flu vaccine is called a trivalent vaccine because

Accepted Answer

Trivalent flu vaccines are designed to protect against three different flu viruses, including two influenza A viruses and one influenza B virus. This is why they are called "trivalent," reflecting the inclusion of three virus strains.

Question 4

Which of the following statements is True about the production of the influenza vaccine?

Accepted Answer

Each statement describes a different, valid method for producing influenza vaccines: using fertilized eggs (A), mammalian cell cultures (B), and recombinant technology involving insect cells (C).

Question 5

Which of the following statements about the component of the flu vaccine and its intended function is True?

Accepted Answer

Formaldehyde is indeed used in the vaccine manufacturing process to inactivate toxins from viruses or bacteria, ensuring they cannot cause disease while still triggering an immune response.

Question 6

In most organisms, the flow of information is from

Accepted Answer

The central dogma of molecular biology describes the flow of genetic information in cells from DNA to mRNA (through transcription) and then from mRNA to protein (through translation), making option A correct.

Question 7

During previous flu seasons, small variations in the influenza virus resulted in the immune system's inability to fully recognize and respond to flu exposure. As a result, vaccine effectiveness could be as low as 30%. This is an example of __________.

Accepted Answer

Antigenic drift refers to the small changes or mutations in the genes of influenza viruses that happen over time. These changes can lead to differences in the virus's surface proteins, making it harder for the immune system to recognize and fight off the virus, even in vaccinated individuals. This is why flu vaccines need to be updated regularly.

Question 8

When two different forms of a virus infect the same cell, the host cell may manufacture viral particles from both viruses to reassemble them into a new form of virus. This process is called __________.

Accepted Answer

Antigenic shift is the correct answer because it refers to the process where two or more different strains of a virus, or strains of two different viruses, combine to form a new subtype having a mixture of the surface antigens of the two or more original strains. This process can lead to significant changes in the virus and potentially result in new viral diseases.

Question 9

Which of the following best describes the action of B cells?

Accepted Answer

All of the statements provided accurately describe the actions and characteristics of B cells. B cells do indeed develop and mature in the bone marrow, carry receptor molecules on their surfaces to recognize antigens, and differentiate into plasma cells to produce antibodies upon encountering an antigen.

Question 10

How does the body recognize "self" cells compared to "nonself" cells?

Accepted Answer

"Self" cells are recognized by the immune system through markers called major histocompatibility complexes (MHCs) on their surface. These glycoproteins help the immune system distinguish between self and nonself cells, preventing it from attacking the body's own cells under normal conditions.

Question 11

When the influenza virus enters into an epithelial cell within the respiratory tract, the infected cell responds by

Accepted Answer

When the influenza virus infects an epithelial cell, the cell presents viral antigens on its surface via MHC molecules. This acts as a signal for cytotoxic T cells to recognize and destroy the infected cell, preventing the virus from spreading further.

Question 12

Why are new flu vaccinations required for each new flu season instead of developing a universal flu vaccine?

Accepted Answer

The flu virus mutates frequently, which means that the antigens (the parts of the virus that the immune system recognizes and attacks) change. As a result, the immune response generated by last year's vaccine may not be effective against this year's virus strains, necessitating the development of a new vaccine each flu season to match the currently circulating strains.

Question 13

Research for a universal flu vaccine tends to focus on

Accepted Answer

Core proteins are the focus because they mutate less rapidly than surface proteins and are more conserved across different influenza strains, making them ideal targets for a universal vaccine.

Question 14

Antiviral medicines target specific stages of the viral life cycle. Which of the following isnot a stage of the life cycle that is targeted?

Accepted Answer

Maturation is not typically targeted by antiviral drugs; most antivirals target stages like attachment, uncoating, or release.

Question 15

New influenza vaccines are being developed that may lessen the effect of the rapid evolution of the viral strains. One way is to develop a universal influenza vaccine that uses ______ as an antigen.

Accepted Answer

A universal influenza vaccine aims to target a protein in the viral capsid because these proteins are more conserved across different influenza strains, making the vaccine potentially effective against a broader range of viruses.

Question 16

Trials of the universal influenza vaccine, H1ssF_3928, began in

Accepted Answer

The trials for the universal influenza vaccine, H1ssF_3928, began in 2019.

Question 17

In the influenza strain nameHongKong/45/2019 (H3N2)-like virus, this was the ______ strain isolated in 2019 in this region.

Accepted Answer

The number "45" in the strain name "HongKong/45/2019" indicates it was the forty-fifth strain isolated in 2019 in this region.

Question 18

For naming purposes, which form of influenza would be characterized by the types of H and N spikes found on its surface?

Accepted Answer

Influenza A viruses are characterized and named based on the types of hemagglutinin (H) and neuraminidase (N) spikes found on their surface, leading to subtypes like H1N1 or H3N2.

Question 19

Which of the following characteristics of life are present in viruses?

Accepted Answer

Viruses have the ability to evolve over time, which is evident from the emergence of new strains and their adaptation to different hosts and environments. This evolutionary capacity is a fundamental characteristic of life. However, viruses lack the other characteristics listed (A, C, D) as they do not process energy and nutrients, respond to stimuli in the same way living organisms do, or maintain an internal environment, since they require a host cell to perform these life processes.

Question 20

Which of the following best distinguishes viral genetic material from the genetic material of a living organism?

Accepted Answer

Viral genetic material can be either DNA or RNA, unlike living organisms which typically have DNA. Additionally, viruses generally have smaller genomes encoding fewer proteins compared to living organisms.

Quiz 7: Understanding Natural Selection, Vaccines, and Viral Reproduction