Exam #4 Biology

Fitness, in reference to the theory of evolution by natural selection, states that individuals with less favorable traits will survive at a greater rate than those without them.

False

The term "antiviral medication" is just another way to refer to a vaccine.

False

Selection favors the most common form of variant for the trait.

Stabilizing selection

Cell-mediated immunity will rely primarily on ____ that can bind to antigen-presenting cells (macrophages) and destroy them.

T cells

When pathogens are ingested by the macrophages and dendritic cells of the immune system, they are digested and a small portion of the pathogen, __________, is attached to the surface of the macrophage.

an antigen

The primary target of the influenza virus is the

epithelial cells lining the respiratory system.

Physical Barriers (innate defenses)

- structures and chemical produced by the body to slow or prevent pathogens from entering the body - ex. Skin, respiratory tract, stomach

Select all of the structural components of a virus.

-genetic material -organelles -plasma membrane and nucleus -protein capsid

Adaptive defenses depend primarily on the activities of _____ and _____, both of which are capable of binding to and recognizing specific targets because they have antigen-specific receptors on their plasma membrane.

-neutrophils -macrophages

Characteristics of living things present in viruses

1. Ability to change over time or evolve 2. Contain genetic material

Line of evidence 1, ______ is the comparison of physical structures between species.

Anatomical evidence

In order to protect the genetic material used in the Moderna and Pfizer vaccines and to allow it to enter a human cell, the genetic material is _____ .

Covered in lipid shell

To prevent overactivity of the immune system, antiviral drugs can bind to ________ to inhibit them.

Cytokines

Line of evidence 4, ______ focuses on embryo comparisons because some features may be present in the embryo that are not apparent in the adult form.

Embryonic evidence

We now know with certainty that vaccinated individuals cannot spread/ transmit the virus to others.

False

Line of evidence 2, _______ is the comparison of genetic and biochemical similarities to indicate evolutionary relationships.

Genetic material

Early in SARS-Cov-2 infection, the virus ____ the activity of the immune system and causes Type 2 alveolar cells to _____ the production of surfactant that normally acts to keep the alveoli from collapsing.

Increase; decrease

Analogous structures evolved independently in different organisms because the organisms lived in similar environments or experienced similar selective pressures.

True

The SARS-Cov-2 virus acts to defend itself from the immune system by covering the spike protein with carbohydrates.

True

Determine which of the following statement(s) are true concerning how flu vaccines are produced.

1. Both trivalent and quadrivalent flu vaccines have the potential to give humans the flu, since they contain weakened versions of the influenza viruses. 2. Individuals should be cautious when it comes to vaccines, since additives such as formaldehyde are present in higher levels than naturally found in the tissues of human bodies.

Characteristics of living things NOT present in viruses

1. Capable of processing energy or materials 2. Maintain an internal environment 3. Contain cell machinery to replicate their genetic material: DNA or RNA 4. Respond to stimuli from the environment

Which of the following ways can SARS-Cov-2 be transmitted from person to person? Please mark all that are correct.

1. Inhalation of viral particles through the mouth 2. Transmission of virus through touching one's eyes 3. Fecal-oral transmission and infection through the digestive system 4. Inhalation of viral particles through the nose

The virus binds to and enters cells with the _____ receptor on its surface.

ACE2

The release of cytokines from lung cells will have which of the following consequences?

Accumulation of fluid around/in the alveoli and decreased gas transport

The avian influenza virus typically infects and transmits the virus among ________ animal species at a time.

One

Evolution is described as the change in heritable traits of a(n) __________ over a period of time.

Population

Shared physical features due to a common ancestor are said to be homologous structures.

True

The virus is covered with a lipid bilayer which is why washing your hands with soap is an effective way to destroy the virus.

True

Which of the following circumstances are necessary for evolution to occur? Select all that apply.

- Competition does not exist, and organisms do not struggle to survive. - The environment does not change.

By recognizing the mechanisms through which organisms change over time, or evolve, we gain insight into which of the following?

- How individual organisms are able to evolve through a single lifecycle - How life originated on planet Earth

Select all of the following that are characteristics that explain the process of natural selection.

- Over time, the frequency of a detrimental trait in the population increases. - Even though an individual is unable to reproduce, they will still be able to pass on their traits to the next generation.

The SARS-Cov-2 virus is unique from other viruses in that B cells and T cells cannot form memory cells to protect us from future infections.

- Prevent the virus from reproducing within an infected cell - Prevent overreaction of the immune system - Prevent the virus from attaching to a lung cel

Protective Proteins

- directly involved in identifying pathogens - some cells phagocytize pathogens - ex. Macrophages and dendrite cells

After the SARS-Cov-2 RNA enters a human cell, the infected cell's ribosome will read viral RNA and build viral proteins such as the M and the S proteins into vesicles using which two organelles? Please mark two options below.

- endoplasmic reticulum - golgi apparatus

Which of the following statements are true concerning how an influenza virus identifies and infects its target cell? Select all that apply.

1. Most viruses are nonspecific to the type of cells they infect. 2. To identify a host cell, a virus is able to produce cytoplasmic extensions that are able to fuse with the plasma membrane of the host cell allowing materials to pass between the host and the virus.

Select all of the following statements that are true concerning the flu vaccine.

1. Since the flu virus never changes, vaccines are created based on influenza surveillance data collected 10 years ago. 2. Vaccines for the flu season are prepared ahead of time and are always effective at protecting humans from the flu.

Which of the following is not a consequence of the appearance of a new SARS-Cov-2 variant?

1. The virus might bind more effectively to human cells and increase the rate of transmission. 2. Current vaccines may no longer be effective at decreasing severe COVID symptoms. 3. Antibodies that a person has from a prior COVID infection may no longer bind to the virus.

__________ has the ability to target cells of the body that are infected with pathogens, while also responding to any pathogens that are free in the blood or interstitial fluid of the body.

Adaptive immunity

Which of the following describes the physical characteristics of the influenza virus?

An RNA virus enclosed in a spherical capsid surrounded by an envelope with spikes

___________ occurs when a mutation causes a change in the H and N spikes on the influenza virus.

Antigenic drift

___________ occurs when two different influenza viruses infect the same host cell, and a new form of the virus is manufactured.

Antigenic shift

While antivirals have specific targets, the role of a vaccine is to coax the immune system to produce __________ when exposed to a safe version of the virus.

Antobodies

Antibody-mediated immunity relies primarily on _____ because they produce antibodies.

B lymphocytes

The following are considered to be evidence of natural selection that Darwin observed aboard the Beagle EXCEPT:

Collecting fossilized remains of extinct animals along the west coast of South America, Darwin believed that all species were created at the same time and did not change form. EVIDENCE? - In regard to biogeography, Darwin discovered similar environments and animals with similar appearances in South America and Europe. -Darwin noted that unique island finch species are descendants from the mainland species that have developed adaptations to survive on the island's food source.

Analogous structure are physical features that look alike and are marks of common ancestry.

False

Herd immunity is most commonly acquired through natural immunity.

False

Natural selection causes mutations.

False

The differences between heritable traits of organisms of a population, also known as _____________, is the primary force driving the mechanism of ________________.

Genetic variation, natural selection

Our immune system typically uses the influenza virus's_____ as an antigen in our adaptive immune response to the influenza A virus.

H spike

The change in the heritable traits of a population continues because natural selection ____________ the frequency of the advantageous trait in the population and _____________ the frequency of detrimental traits.

Increases; decreases

Infected cells will release _____ that will signal to macrophages to destroy the cell.

Interferon

All of the following factors except _________ act to prevent us from reaching COVID herd immunity.

Limiting social interactions and wearing a mask

We do not currently have a vaccine approved for young children. How does this affect herd immunity?

More adults need to be vaccinated as a result to reach herd immunity

The SARS-Cov-2 virus uses ____ as its genetic material that is protected and stabilized by ____ proteins that bind to it.

RNA; N proteins

The ____ proteins of SARS-Cov-2 are responsible for binding to human cells.

S

Line of evidence 3, ______ is a line of evidence that provides information on transitional species.

The fossil record

Antigen-presenting cells present the antigens from the vaccine to Helper T cells and B cells.

True

Like human cells and DNA viruses, the SARS-Cov-2 virus can proofread and correct mutations that occur during replication.

True

Macrophages, Dendritic Cells, and Neutrophils are considered non-specific in their response to destroying pathogens.

True

The glycoproteins of the plasma membrane involved in identifying self are collectively called major histocompatibility complexes.

True

Transitional fossils not only capture the "in-between" forms on the path to present-day species, but they can also provide an indication of the timeline of the changes that took place.

True

Which of the following statements accurately describes how viruses reproduce?

Viruses are typically a piece of genetic material encased in a protein capsule. They are only capable of reproducing once inside a living host cell.

Instead of using an inactivated virus for a vaccine, a vaccine could instead contain mapped viral genes in the form of _______ like both the Moderna and Pfizer vaccines do.

mRNA

Direct effects of influenza virus on body systems

1.