Exam 5 Bio

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

45th

Mucus traps pathogens that are later coughed or sneezed away. This is an example of activity from the body's ________ line of defense.

First line of defense

If you were observing embryonic structures of a tortoise, a chick, and a human, which of the following would not be a similar structure?

Five finger digits

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 a protein in the viral capsid as an antigen.

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 __________.

Viral recombination

An immune system cell that binds to an antigen is called a(n) ________.

immunoglobulins

Thymus, spleen, red bone marrow and lymph nodes are associated with the

lymphatic system.

The cycle of viral infection that will rapidly result in the death of a bacterial cell is called the ______ cycle.

lytic cycle

The process of evolution of the influenza virus that results from the infection of two viruses in the same cell is called Antigenic ______.

antigenic drift

Relationship between mutations and natural selection:

A mutation in the genetic material may or may not have an effect on the protein. A mutation may result in the death of an organism or cell. A mutation may result in a variation of a trait that may be more advantageous.

Which of these best describes a virus?

A nonliving complex of RNA or DNA protected by a protein coat.

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

Antigens serve as labels that enable the immune system to distinguish between a normal interaction (self) and an encounter with a foreign threat (nonself).

When a macrophage presents an antigen with an MHC-II protein, it interacts with ____ T cells.

CD8+

In most organisms, the flow of information is from _____ to _______ and to __________.

DNA to RNA to protein

A certain species of butterfly varies in color from white to dark blue. The birds found in the same area feed on the white or lightly colored butterflies, leaving butterflies that are darkly colored. This is an example of what type of selection?

Directional selecion

What type of cells would a flu virus most likely target as the means of entry into the body?

Epithelial cells

If an influenza strain mutation results in the production of different H spikes, this could be life threatening because

H spikes are used as antigens to identify the virus by the immune system.

Which structure on the influenza virus provides attachment to the surface of the targeted host cell?

Hemagglutinin

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

Influenza A

What are the challenges in developing an annual influenza vaccine?

Influenza evolves rapidly, It takes six months to develop the vaccine and there are many strains of influenza.

The chickenpox virus can remain latent in host cells by integrating its DNA into the host cell genome. This virus uses the ______ cycle as its main life cycle pathway.

Lysogenic

The ______ glycoproteins are presented by all nucleated cells and an identification tag. The ______ glycoproteins are only presented by cells to provide the link between nonspecific immune responses.

MHC I and MHC II

Antiviral medicines target specific stages of the viral life cycle.

Maturation is not a stage of the life cycle that is targeted.

The adaptive immune response can remember past exposures to pathogens by holding ______ B cells in reserve.

Memory b cells

A primary source for new, unique genes in a population is ______________.

Mutation

What structures represent a first line of defense against pathogens?

Skin, tears and mucus

__________ and ___________ cells ingest, digest, and provide an antigen for the immune system to respond?

T and B lymphocytes

Adaptive immunity differs from the innate immune system in its abililty to respond to specific pathogen antigens.

The antigens trigger both antibody-mediated immunity and cell-mediated immunity.

The enzyme ______ polymerase does not have a high degree of fidelity, and therefore more mutations can be introduced in the genetic material of RNA viruses.

The cellular RNA polymerase II enzyme

The flu virus may impact the respiratory system in the following ways:

The immune system prompts a decrease in blood flow, which results in the lungs becoming dry. A hacking cough can be produced. The proteins produced by the virus interfere with the ability of epithelial cells to move materials in and out of lung tissue, resulting in fluid buildup in the lungs. Epithelial cells see an increase in function as they try to adapt to the viral load of surrounding cells.

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

The viral genome is either DNA or RNA and encodes for fewer proteins.

Memory B cells are developed after a primary response.

These memory cells are activated during a secondary response to produce a higher amount of antibodies, have a quicker recovery time from an infection and have an overall more efficient immune response.

Three methods for the production of the influenza vaccine.

Viruses are injected into fertilized eggs, incubated, then viral particles are extracted, purified, deactivated, and used to make vaccines. Viruses are injected into mammalian cells, then viral particles are extracted, purified, deactivated, and used to make vaccines. A protein responsible for the H spikes of the flu virus is added to a harmless virus that infects insect cells, causing them to produce massive amounts of H spike protein. The extracted H spike protein is then purified and used to make vaccines.

Which immune system protects the body from its own cancerous cells?

acquired immune system

The immune system's role is to _______________.

actively seek and destroy pathogens

When the influenza virus enters into an epithelial cell within the respiratory tract, the infected cell responds by posting ___________ on its cell surface, acting as a flag for the ____________ T cells to destroy it.

antigens, cytotoxic

Darwin was very interested in the observation that animals on distant and isolated landmasses appeared to be related to animals on the mainlands. However, despite their similar appearance, the animals were indeed not related. This is an example of

biogeographical evidence.

Which specific defense mechanism defends primarily against antigens in body fluids?

cell-mediated immune system

B cell activation, through antibody-mediated immunity, results in the production of memory ___ cells, secretion of _____ and production of ________ cells.

cells , plasma cells and memory cells

B cells develop and mature in the bone marrow. B cells carry receptor molecules on their cell surfaces and B cells

change into plasma cells after encountering an antigen and then produce antibodies.

The most common flu vaccine is called a trivalent vaccine because it

contains three different strains of inactivated viruses.

One of the four mechanisms of the innate immune defenses is the inflammatory response. Its role is to increase blood flow to the infected area

isolate the infection to a limited area and allow fluid, containing cells from the immune system, to reach the infected area.

The influenza vaccine elicits an immune response by presenting the body with a

killed version of the virus or antigens specific to the virus.

The activities of macrophages are part of the nonspecific response against disease and stimulate

phagocytic neutrophils.

Antigenic shift causes rapid change in the influenza virus, can result in an influenza strain that the human immune system has not been exposed to & was responsible for

the 1918 Spanish flu pandemic.

T cells undergo further maturation in the ________ gland.

thymus gland

Physician Edward Jenner promoted the use of cowpox, a harmless pathogen related to the dangerous smallpox virus, as a vaccination to provide patients immunity from future smallpox epidemics. Today a similiar method is used with the influenza vaccine. This is an example of __________ immunity.

Active immunity

All viruses are made up of two components. These components are

Nucleic acid and protein coat

The influenza virus targets epithelial cells that line the respiratory tract. What is the normal function of epithelial cells?

They form boundaries between the body tissue and internal environments

What is the correct sequence of events in viral reproduction?

attachment, penetration, uncoating, replication, assembly, and release

One method of constructing an influenza vaccine is to use an influenza strain that has been modified by removing proteins that contribute to its virulence. This process is called __________.

attenuation

Viral genetic material exchange between different populations would result in the

formation of an influenza virus that would threaten humans.

The scientific definition of evolution refers to changes in a ______ over time.

population

As influenza A progresses through the respiratory tract, the ______ spikes of the virus identify host epithelial cells and attach to the cell surface.

H spikes

Which of the following best outlines the path of influenza through the body?

Nostrils, pharynx, larynx, trachea, bronchus, bronchiole, lungs, alveoli

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 __________.

antigenic drift

During an infection, the immune system alerts the organ systems of the body by producing ______________. These are also responsible for the body aches felt during an influenza infection.

cytokines

The ______ process to make influenza vaccines, only uses a small portion of the H spike protein that helps the immune system identify the actual virus.

egg-based production process

The immune system works very closely with the ______ system to return filtered fluid back to the circulatory system.

lymphatic system.

What is the first reaction of the body due to the influenza virus disrupting the normal function of the epithelial cells in the respiratory system?

Fluid accumulation in the lungs

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

Ability to evolve over time

Biologists, who study _genetics, ecosystems and systematics_____, are interested in understanding evolution as process of life.

genetic material, ecosystems, systematics, ALL OF THE ABOVE (CORRECT)

Cytotoxic T cell activation by cell-mediated immunity results in the ______ and apoptosis of infected cells.

production of memory T cells

What is the role of interleukin in the immune response?

The primary function of interleukins is, therefore, to modulate growth, differentiation, and activation during inflammatory and immune responses.

What is the role of histamine in the immune response?

Histamine affects the maturation of immune system cells and alters their activation, polarization, chemotaxis, and effector functions.

Structures that are passed on from a common ancestor, such as the bone structure of a limb, are called ______ structures. Structures that have the same function but evolved independently, such as wings of bats and birds, are called ______ structures.

Homologous, analogous

Birds and insects both have wings, but we do not consider this similarity as evidence of relatedness because the wings are not ___________ structures with a common ancestral origin.

Homologus

What is the role of interferon in the immune response?

Interferons are proteins that are part of your natural defenses. They tell your immune system that germs or cancer cells are in your body.

Consider the following scenario: A fish that was normally found in freshwater has evolved and can now survive in brackish (containing a mixture of fresh and salt) water.

The evolution of the fish would affect all other levels of biology, including other populations, communities, and ecosystems.

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

The flu virus mutates frequently enough that last year's vaccination will no longer target currently circulating flu strains.

Research for a universal flu vaccine tends to focus on core proteins,

as they do not mutate as rapidly as H and N spikes and they tend to be similar between different influenza strains.

The cytochrome c protein is sometimes used to describe the evolutionary relationship between species. This is becaus

the closer the DNA sequences are between species, the closer they are related on an evolutionary scale.