Evolution of Viruses

Which of these are ways a new form of the flu can appear?

- Antigenic drift via mutation that changes the viral spikes - Antigenic shift via recombination of viral characteristics from multiple viruses infecting animal hosts

Select the description of the two treatment options being developed against the influenza virus.

- antiviral medicines that target various stages of the life cycle of the virus - a universal flu vaccine that targets core proteins instead of viral spikes

Which of these describes developments in fighting the influenza virus?

Scientists are looking at ways to get around the rapid evolution of the virus by targeting proteins that are slower to change.

When are strains of influenza chosen for vaccine production in the Southern hemisphere?

September prior to the start of flu season.

In the quest to produce effective influenza vaccinations, what are the consequences of evolution in the virus?

Sometimes the vaccines are not effective because predictions about the path of the viral evolution don't hold up.

Which characteristic of proteins allows influenza to specifically target its host cells?

Specific, complex, three-dimensional shape

Perforins are secreted by ______ cells and function by ______.

T cytotoxic, making a hole in the membrane of the target cell

The forelimbs of modern vertebrates are homologous structures, meaning that they may have changed evolutionarily to perform different functions, but they

evolved from the same body part in a common ancestor.

If a favorable mutation increases the ability of an individual to reproduce then natural selection would

favor this variation.

The process of natural selection

favors some mutations, when they increase fitness.

Reproductive success among individuals with favorable traits, which they pass on to the next generation is often described using the term

fitness

One of the components of the process of natural selection is based upon an individual's ability to compete for resources in order to survive and reproduce. This component addresses the

fitness of individuals.

Select all that apply. If you were to create a list to summarize the scientific evidence that supports the idea that populations evolve over time, which of these items would you include?

fossils homologous structures DNA molecules

Even though the soft parts of an organism usually decompose when it dies, its hard parts may become mineralized to form ___ over time.

fossils or fossil

The quadrivalent influenza vaccine contains

four different influenza strains: three found in the other injectable form of the vaccine, and B/Phuket/3073/2013 (Yamagata lineage) virus.

When an organism dies, its ______ may become mineralized, forming fossils.

hard parts

Adaptive immune responses are activated when

helper T cells recognize the combination of a major-histocompatibility complex and an antigen on the surface of a macrophage.

Structural similarities due to common descent are seen in

homologous structures.

After viruses are harvested from the liquid portion of infected chicken eggs,

they are inactivated (killed).

How do antiviral medicines target viruses?

they target the viral life cycle

The trivalent influenza vaccine contains

three different strains of influenza, which are chosen specifically each year.

What is the role of clotting factors in the inflammatory response?

to close off the wound

In the case of severe infection, what is one of the roles of neutrophils in the inflammatory response?

to release cytokines that recruit more immune cells

Even though there are gaps in the fossil record, some of the most direct evidence for evolution comes from fossils called ______ fossils, which can show relationships between groups.

transitional

Select the form(s) of flu vaccine that contain inactive (killed) viral particles.

trivalent vaccine quadrivalent vaccine

The target cells of influenza virus, which are epithelial cells in the respiratory system, are identified by the virus because

viral capsid proteins (spikes) identify specific glycoproteins embedded in the host cell membrane.

An obligate intracellular parasite that can only replicate itself using the cellular machinery of a host cell is called a(n)

virus.

How many people were infected by the Spanish flu in 1918?

~ 500 million

During the process of choosing strains for the annual influenza vaccine, which of the following characteristics is most likely to qualify a strain to be included?

a strain that has a high potential for causing global pandemic

Which type of immunity is capable of identifying infected body cells as well as pathogens in the blood because it responds to the presence of specific antigens?

adaptive immunity

Which type of immunity is capable of remembering a past immune response?

adaptive immunity

Many fields of biology study evolution, because evolution is involved in __ levels of biology.

all

During the inflammatory response, histamine

allows white blood cells and clotting factor to be delivered quickly because blood flow is increased.

A virus can be defined as

an obligate intracellular parasite.

Structures that serve the same purpose but evolved independently are called _____ structures.

analogous

Adaptive immune responses are activated when a macrophage engulfs and digests a pathogen and then displays a specific ___ on its surface.

antigen

During the adaptive immune response, cytotoxic T cells

attack and kill other cells.

The field of ___ studies life.

biology

The study of life is called

biology

To do so, one the roles of the immune system is to monitor ___ for the presence of pathogens.

bodily fluids

An influenza virus targets a host cell using its

capsid proteins.

Evolution, by its scientific definition, refers to

changes in a species or population over time.

The study of homologous and analogous structures, also called ___ anatomy, studies the similarity of both living and fossilized species' structures to infer evolutionary relationships.

comparative, compare, or comparison

Which molecule plays the role of a molecular tag during innate immune defense, identifying pathogens for destruction by the immune system?

complement proteins

Select all of the characteristics of a viral envelope.

composed of remnants of host cell plasma membrane assists in attachment and entry into host cell surrounds the capsid

The proteins that form the viral capsule are sometimes called

core proteins.

The various chemical signals of the immune response, which include small proteins like histamine, are collectively called ___.

cytokines or cytokine

The importance of transitional fossils is that they

demonstrate relationships between two groups of organisms.

Which of these is a role of complement protein during innate immune response?

destroying bacterial cells by creating holes in its membrane

Which type of selection favors one extreme variant for a trait within a population?

directional selection

Select all of the characteristics of influenza viruses.

envelope RNA capsid spikes

The influenza virus targets which types of cells in the human body?

epithelial cells

What is the primary target of the influenza virus?

epithelial cells

From changes in cells over time to the interactions of ecosystems, ______ plays a role in all levels of biology.

evolution

The scientific definition of ______ refers to changes in a species or population over time.

evolution

Transitional fossils can tell us about the ______ among groups of organisms.

evolutionary relationships

Which of these can be attributed to the outbreak of the Spanish flu in 1918?

a new variant of the influenza virus

Which of these offers an explanation of the relationship between biology and evolution?

Evolution is the unifying theme of biology. This process helps to explain nearly every aspect of the biological sciences.

Adaptive immunity has the ability to target

- pathogens moving freely in the blood or body fluids. - infected body cells.

Select the examples of innate immune defenses.

- the removal of dead cells and pathogens via neutrophils during the inflammatory response - bacteria on the surface of the skin inhibit bacterial growth - the identification and destruction of pathogens via macrophages - hydrochloric acid in the stomach destroys bacteria and other pathogens

What is an antiviral medication?

A medication that treats viruses by targeting specific aspects of their life cycle.

Which of these explains one of the processes by which the influenza virus evolves?

A mutation that changes the viral spikes is introduced into the genetic material.

Select all of the criteria used to choose influenza strains for annual vaccines.

A strain's potential to cause a worldwide pandemic Ability to produce an effective vaccine against the strain

What is a universal flu vaccine?

A vaccine that provides immunity against all forms of the virus

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

Why is Archaeopteryx considered to be a transitional fossil?

Because it has features of both birds and dinosaurs

Why is it challenging to choose influenza strains to include in vaccines?

Because the virus can evolve quickly, and may have changed before flu season

Which of these choices explains how the process of evolution relates to the study of biology?

Biology is the study of the natural world and the process of evolution is a part of that world.

The immune system and the lymphatic system work closely together to protect the body from ____________ .

Blank 1:

The lymphatic system is also involved in the production and maturation of immune system cells called ____________ .

Blank 1:

The ____________ consists of several organs and tissues that are involved in filtering and cleaning the ____________ and interstitial fluids of the body.

Blank 1: Blank 2:

The lymphatic system returns ____________ from the tissues of the body back to the ____________ . By monitoring the return of these fluids in the ____________ of the body, the ____________ detects the presence of pathogens.

Blank 1: Blank 2: Blank 3: Blank 4:

The Spanish flu infected one-third of the world's population, killing between ____ and ___ million people.

Blank 1: 30 or thirty Blank 2: 50 or fifty

In all organisms, except retroviruses, the flow of information is from ___ to ___ to ___ .

Blank 1: DNA or deoxyribonucleic acid Blank 2: RNA or ribonucleic acid Blank 3: protein, proteins, polypeptide, or polypeptides

The process of natural selection and the idea of descent with modification were proposed by ___ after he notably studied beak size in finches on the Galapágos Islands. The idea that changes in a population over time could lead to the formation of a new species was proposed by ___ after his study of biogeography in the South Pacific Islands.

Blank 1: Darwin or Charles Darwin Blank 2: Wallace, Alfred Wallace, or Alfred Russel Wallace

The ____________ is responsible for protecting our bodies from harmful substances and pathogens that enter the body.It has a remarkable way of adapting to the constantly evolving structure of ____________ .

Blank 1: Immune System Blank 2: Pathogens

Medications that treat viruses by targeting the life cycle of a virus are called ___ medications.

Blank 1: antiviral

Another term used to describe the proteins that make up the viral capsule is ___ protein.

Blank 1: core

It is difficult to develop a universal flu vaccine in large part because the flu virus is able to ___ very quickly.

Blank 1: evolve, change, or mutate

The mineralized traces of formerly living species are called ___.

Blank 1: fossils or fossil

Another role of the immune system is for the cells of the ___ to interact with all of the tissues and organs of the body and to distinguish bodies' cell from those of ___.

Blank 1: immune system Blank 2: invaders

The immune system cells may be ___ and involved in the general immune response or are specific and are capable of targeting a ___ type of a pathogen

Blank 1: nonspecific Blank 2: Specific

When fossils are arranged and compared according to their age, from ___ to ___, successive evolutionary change becomes apparent.

Blank 1: oldest, older, old, earliest, ancestors, past, or ancestral Blank 2: youngest, younger, young, newest, most recent, new, latest, descendants, present, or recent

A new form of the flu could appear via antigenic ___ in animal hosts like pigs and birds, or via antigenic ___ caused when mutations alter the viral spikes.

Blank 1: shift Blank 2: drift

A vaccine that would treat multiple strains of the flu is currently in research and testing phases. This type of wide-acting vaccine is referred to as a(n) ___ vaccine.

Blank 1: universal

Which of these molecules contain instructions for specific traits?

DNA RNA

All known living things use ___ as their genetic material.

DNA or deoxyribonucleic acid

Normally, the flow of information in a cell is in which direction?

DNA to RNA to protein

Smallpox, Hepatitis B, and mononucleosis are examples of which type of virus?

DNA viruses

Which of these scientists is one of the two who independently proposed the mechanism for evolutionary change?

Darwin

Which is the correct comparison of the sources and ideas of Charles Darwin and Alfred Russel Wallace?

Darwin studied biogeography and finches and proposed the theory of natural selection. Wallace studied biogeography and proposed the idea of speciation.

Select all of the following which are characteristics of all viruses.

Genetic material Protein capsid

Which of the following are structural components found in all viruses?

Genetic material and a capsid

Which of these best explains the role of the immune system in protecting the body from pathogens?

It destroys pathogens and infected cells, produces antibodies, and targets infected cells.

Which of the following statements are true of acute inflammatory response?

It increases blood flow to the site. It is the body's initial reaction to tissue damage.

If you were to explain the role of the immune system in protecting the body from pathogens, which of these would you include in your explanation?

It produces antibodies. It destroys infected cells. It destroys pathogens.

What is the role of histamine in the inflammatory response?

Its release causes the capillaries to leak fluid that slows pathogen movement while also increasing blood flow.

Select the four categories of innate immune defenses.

Phagocytes and natural killer cells Protective proteins Barriers to entry Inflammatory response

Because individuals vary in their traits, compete for resources, and vary in their fitness, the final component of natural selection results. What is this final step?

Populations become adapted to their environment.

Influenza, Polio virus, Rabies virus, and Ebola are all examples of ______ viruses.

RNA

The genetic material of all living things is DNA, as far as we know. Viruses, however, may also use ______ as their genetic material.

RNA

Which genetic material contains a five-carbon sugar called ribose and is single-stranded?

RNA

Viruses can have which of the following forms of genetic material?

RNA DNA

Influenza is a(n) ______ virus surrounded by ______.

RNA; a capsid and an envelope

Which of these contains more genes?

The genome of a living thing

Which statement summarizes the scientific evidence that supports the idea that populations evolve over time?

The idea that populations evolve over time is supported by physical evidence (including fossils, homologous structures, and embryonic development) and chemical evidence (including DNA and protein sequences).

Which best describes the consequences of evolution on producing effective influenza viruses?

The process is more challenging because the virus evolves quickly.

Which of these is the most common form of the influenza vaccine?

The trivalent injectable vaccine

How does the influenza A virus target a host cell?

The virus has H spikes that are specific to receptors on the surface of the host cell.

Which of these makes it difficult to develop a universal flu vaccine?

The virus has a high mutation rate.

Which of these is a description of how the flu affects the body systems?

The virus releases proteins that disrupt respiratory epithelial cells and the immune system releases cytokines in response to the virus that cause multiple symptoms in the respiratory and other body systems.

Which of the following describes how the flu affects the respiratory system?

The virus targets epithelial cells in the respiratory system, producing proteins that interfere with their function.

Which of these explains one of the processes by which the influenza virus evolves?

Two different forms of the same virus infect the same host cell and a new virus is created with parts of each form.

Select all of the explanations of how influenza vaccines are produced.

Using mammalian cell cultures Using H spike proteins to infect insect cells Using fertilized chicken eggs

During his voyage on the HMS Beagle, which of these observations did Darwin note as evidence for natural selection?

Very similar species of large, flightless birds in South America and Africa

Which of these best explains how influenza vaccines are produced?

Viral strains are selected well ahead of flu season based on their threat and our ability to make a vaccine against them. Vaccines are then produced using one of three common methods. This process can take up to six months.

Which is the best general explanation of how viruses reproduce?

Viruses use one of two life cycles, both of which take over a host cell's resources, in order to copy themselves.

Which of these explains the general process of how viruses reproduce?

Viruses use the machinery of their host cell to make copies of themselves.

Which of these scientists is one of the two who independently proposed the mechanism for evolutionary change?

Wallace

Select all of the following components of a flu vaccine.

Weakened viruses or inactive viral particles Three to four strains of the influenza virus Additives, including antibiotics, stabilizers, and remnant egg proteins

Which of the following is a pair of analogous structures?

a butterfly's wing/ a bird's wing

What is a cytokine?

a chemical signal of the immune response

A viral genome contains ______ genes than the number found in living organisms.

a fraction of

During the inflammatory response, macrophages

identify and destroy bacteria or viruses in the vicinity of the wound.

Because it includes the body's external barriers and cellular and chemical mechanisms that add general protection against pathogens, ___ immunity is also referred to as nonspecific immunity.

innate

General, nonspecific immune defense against pathogens is called

innate immunity

When using fertilized chicken eggs to produce flu vaccines, the virus replicates

inside the fertilized eggs while the incubate for a few days.

The genetic material of living things, DNA, or of a virus, which may be DNA or RNA, contains

instructions for specific traits.

Which of the cytokines typically associated with immune response signals nearby cells when a cell has been infected by a virus?

interferon

Which of the cytokines commonly involved in immune responses is a glycoprotein that helps to regulate the general immune response?

interleukin

Which quality of the flu virus makes it difficult to choose influenza strains to use in vaccines?

its potential to evolve quickly

Antiviral drugs

keep the virus from multiplying inside host cells by interfering with the viral life cycle.

The cells that identify and destroy pathogens during an inflammatory response are called

macrophages.

The ______ flu vaccine can cause some flu-like symptoms.

nasal spray

Which of these is an example of innate immune defense?

natural killer cells that destroy body cells infected with pathogens

In support of the idea that species change over time, Darwin proposed a four step process called

natural selection.

The process that drives evolution, and relies on variation in individuals, competition among individuals, differences in individual fitness, and adaptation to the environment, is called

natural selection.

What is the function of neutrophils in the inflammatory response?

phagocytize bacteria

All viruses have genetic material and a

protein capsid.

Perforin is a(n)

protein that, once inserted into the target cell's membrane. forms channels through the membrane.

Because of their complex three-dimensional shapes, the ___ attached to the capsid of a virus are specific in the molecules they identify on a host cell.

proteins, spikes, protein, or spike

Cytotoxic T cells

recognize targets by their antigens, bind to and directly destroy them.

What occurs because of the inflammatory response?

redness at site of infection or injury swelling at site of infection or injury

With regards to evolution, fitness is most closely related to successful

reproduction.

During the inflammatory response, clotting factors

seal off damaged capillaries.

While aboard the HMS Beagle, Charles Darwin observed which of these as evidence for natural selection?

similarity in overall appearance in finches, but variation in beak shape and size

Which type of selection favors the most common variant for a trait in a population?

stabilizing selection

Which of the following is a characteristic of a viral envelope?

surrounds the viral capsid

Select all that apply to complete this sentence. Fossils often form when the ______ of once-living organisms mineralize over time.

teeth shells bones

Which of these is an example of an innate immune defense?

the body's initial inflammatory response to injury

The genes of a living thing contain

the information needed to produce proteins and RNA.

The genes of a virus contain

the instructions needed to manufacture its protein capsid and surface spikes (if it has spikes).