Influenza

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

30; 50

Explain one of the processes by which the influenza virus evolves

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

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

Epithelial cells lining the respiratory system

What are the structural components found in all viruses?

Genetic material and a capsid

What is a component of the process of natural selection?

Individuals vary in their traits.

What 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.

What methods are used to produce influenza vaccines?

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

What are subunit vaccines?

Vaccines that contain only the antigens that best stimulate the immune system

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

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

A virus can be defined as ...

an obligate intracellular parasite

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

analogous

Fossils often form when the ___ of once-living organisms mineralize over time

bones, teeth, shells

An influenza virus targets a host cell using its ...

capsid proteins.

selective pressures

environmental resistance factors affect which individuals survive and reproduce

Structural similarities due to common descent are seen in ___

homologous structures.

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

instructions for specific traits.

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

it contains three different strains of inactivated viruses.

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

lytic

Increased blood flow and collection of immune cells in the respiratory tissues causes ...

matches

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

nasal spray

All viruses have genetic material and a ...

protein capsid.

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

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

reproduction

What is an example of analogous structures?

A butterfly's wing/ a bird's wing

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

A new variant of the influenza virus

What are the characteristics of a viral envelope?

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

What is the correct sequence of events in viral reproduction?

Attachment, penetration, biosynthesis, maturation, and release

How does 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 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.

Charles Darwin; Alfred Russel Wallace

Homologous structures represent which form of evidence supporting the theory of evolution?

Comparative anatomy

Characteristics of a viral envelope

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

Proteins produced by the flu virus that disrupt the normal function of epithelial cells cause ...

Congestion/trouble breathing from fluid accumulation in the lungs

The genes of a living thing ...

Contain the information needed to produce all of the proteins for cellular metabolism and the information needed to produce RNA.

The genes of the viral genome ...

Contain the instructions needed to produce a protein capsid, and, in some cases, contain the information needed to produce surface glycoproteins.

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

Directional selection

Characteristics of DNA

Double-stranded, nitrogen bases are A,T,G and C, and the only genetic material found in known living things

Examples of RNA viruses

HIV, Ebola, Influenza, Polio, Measles, Rabies, Rhinovirus (cold), and Coronavirus

H Spikes

Hemagglutinin; 17 subtypes; elicit an immune response and is part of the influenza vaccine

If you were to create a list to summarize the scientific evidence that supports the idea that populations evolve over time, what items would you include?

Homologous structures, DNA molecules, and fossils

What are the steps in producing vaccines with fertilized eggs?

Injection, incubation, extraction, inactivation, purification

Cytokines released in the immune response cause ...

Loss of appetite

N Spikes

Neuraminidase; 10 subtypes; Functions as an enzyme to let the new viral particles out of the host cell

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.

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

RNA

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

RNA and DNA

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

Characteristics of RNA

Single-stranded, nitrogen bases are U,A,C, and G, and not used as the genetic material of any known living things

Examples of DNA viruses

Smallpox, chickenpox, herpes, Hepatitis B, HPV, and mononucleosis

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

Specific, complex, three-dimensional shape

Alfred Russel Wallace

Studied biogeography in the South Pacific Islands, and proposed the concept of speciation

Charles Darwin

Studied biogeography on the west coast of South America and the Galapágos Islands, proposed descent with modification, proposed the process of natural selection

What is a characteristic of a viral envelope?

Surrounds the viral capsid

What is 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).

What is the consequences of evolution on producing effective influenza viruses?

The process is more challenging because the virus evolves quickly

What is the most common form of the influenza vaccine?

The trivalent injectable vaccine

What 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

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.

How does the flu affect the body's 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.

Why is the influenza virus a good model for the study of evolution?

The virus reproduces rapidly, the genetic material of influenza changes quickly, and the virus is responsible for a human disease.

How are influenza vaccines 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.

What 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.

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

all

Evolution, by its scientific definition, refers to ___

changes in a species or population over time

Cytokines produced by the immune system that restrict blood vessels in the skin cause ...

chills

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

Flu symptoms like nausea, fever, and chills are caused by ...

cytokines release during the body's immune response to the influenza virus.

The importance of transitional fossils is that they ___

demonstrate relationships between two groups of organisms.

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

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

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

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

hard parts

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

In the influenza strain name A/Singapore/INFIMH-16-0019/2016 A(H3N2)-like virus, this was the ______ strain isolated in 2016 in this region.

nineteenth

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

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

One of the steps in the process of natural selection involves the individual's struggle to exist, which is based upon competition for available ___ like food and shelter.

resources

Inflammation in the epithelial tissues caused by the proteins release by the flu, which interfere with epithelial cell function causes ...

sore throat

The genes of a living thing contain ...

the information needed to produce proteins and RNA.

The trivalent influenza vaccine contains ...

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

The influenza proteins that target host cells have a complex, __________ shape.

three-dimensional

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

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

virus

What are the criteria used to choose influenza strains for annual vaccines?

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

What are the components of a flu vaccine?

Additives (including antibiotics, stabilizers, and remnant egg proteins), weakened viruses or inactive viral particles, and three to four strains of the influenza virus

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

What molecules contain instructions for specific traits?

DNA and RNA

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

DNA to RNA to protein

What is the primary target of the influenza virus?

Epithelial cells

What is 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

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.

Which of the following are correct regarding antigenic drift?

It is due to minor mutations in the structure of the H and N spikes

What are two true statements concerning evolution?

It is the result of heritable change in DNA and is one of the unifying themes in biology

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

Its potential to evolve quickly

Cytokines produced by the immune system that break down muscle fibers and cause fluid accumulation cause ...

Joint and muscle aches

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

RNA

What are the characteristics of influenza viruses?

RNA, spikes, envelope, and capsid

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

RNA; a capsid and an envelope

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

Stabilizing selection

How does the flu affect the respiratory system?

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

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

They form boundaries between the body tissue and internal environments.

What is the general process of how viruses reproduce?

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

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

a fraction of

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

a protein capsid and genetic material, in the form of either RNA or DNA

Antigenic

a substance, when introduced into the body, stimulates the production of an antibody

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

fossils