Bios 1063 exam 1
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
adaptive defenses depend primarily on the activities of
B and T cells
focuses on embryo comparisons because some features may be present in the embryo that are not apparent in the adult form.
embryonic evidence
cells directly involved in identifying pathogens
phagocytes and natural cells
When the influenza virus enters into an epithelial cell within the respiratory tract, the infected cell responds by
posting antigens on its cell surface, acting as a flag for the cytotoxic T cells to destroy it.
The first time the immune system comes into contact with the antigen, it is slow to produce antibodies
primary response
proteins that complement certain immune responses
protective proteins
Antiviral medicines target the enzyme that allows the virus to remove the genetic material from the capsid.
targeting uncoating
The influenza name A/Singapore/INFIMH-16-0019/2016 A(H3N2)-like virus, indicated that is the the ______ form of the virus.
A
Which of the following statements explains the 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 the following best describes a virus?
A nonliving complex of RNA or DNA protected by a protein coat
Historically, viruses have not been classified as living organisms. Which of the following characteristics of life excludes viruses from being classified as living organisms?
Ability to process energy and materials
- specific - produce antibodies to target specific antigens in the fluids of the body
B lymphocytes
Proposed that the Earth's surface is dynamic and constantly changing
Charles Lyell
Proposed that evidence from animal development and animal breeding shows that species may evolve over time
Erasmus Darwin
he Proposed the idea of catastrophism; he believed that all species were created at the same time, yet catastrophic events have caused some species to go extinct and studied the fossil record and noticed that fossils showed a succession of different forms of life over time
Georges Cuvier
Which of the following is true concerning the evolution of COVID-19?
It evolves quickly because it is an virus It has a high mutation rate because it is an RNA virus New strains can jump from an intermediate species to humans
Proposed the idea referred to as inheritance of acquired characteristics
Jean-Baptiste Lamarck
_______ in a gene can produce a new or altered allele that may encode for a unique trait
Mutation
When natural selection increases the frequency of the advantageous trait in the population and decreases the frequency of detrimental traits, this is an example of
Populations become adapted to their environment
Wallace shared his ideas with Darwin, which led to the book, On the Origin of Species. Wallace contributed his biogeographical studies of the __________.
South Pacific Islands
- specific - target cells that have been infected by a specific pathogen
T lymphocytes
Which of the following is a challenge in developing an annual influenza vaccine?
The flu virus evolves rapidly. It takes at least 6 months to develop a vaccine. There are many strains of influenza.
he Stated that populations sometimes increase at rates faster than their food supply can increase, thus creating competition
Thomas Malthus
- contains diff strains of 3 viruses - contains 2 A viruses - contains 1 B virus - virus particles are inactivated and incapable of reproducing
Trivalent vaccine
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.
All viruses are made up of two components. These components are
a protein capsid and genetic material.
The immune system's role is to
actively seek and destroy pathogens
Structures that have the same function but evolved independently, such as the wings of bats and birds, are called ______ structures.
analagous
the comparison of physical structures between species
anatomical evidence
a form of adaptive immunity that involves the B lymphocytes which are involved in the production of antibodies
antibody mediated immunity
- Because the influenza virus is an RNA virus, it must undergo reverse transcription in order for the host cell to use its genetic material to make the new viruses. Since this process is not heavily regulated, it has the potential to introduce new mutations within the genetic materials of the virus. - Small changes in the genes of influenza viruses can lead to changes in the surface proteins. These small changes produce viruses that are closely related to one another.
antigenic drift
when a mutation causes a change in the H and N spikes on the influenza virus.
antigenic drift
- A new form of the influenza virus originates in an animal host. Due to humans' close proximity to these animals, it is possible for viruses to undergo reassembly and produce a new form of the virus, which can infect humans. - Abrupt, major changes in the influenza virus leads to new H and N spikes on the influenza virus.
antigenic shift
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 __________.
antigenic shift
The specific immune system recognizes _______________ found on the surface of the pathogen.
antigens
The activities of macrophages
are part of the general immune system.
skin, the mucus membranes of different organ systems, and stomach acids are ways to inhibit or slow the growth of microbes
barriers to entry
Component 2, the ,_________ is a protein coat that surrounds the genetic material.
capsid
a form of adaptive immunity that uses 2 types of cells, helper T cells and cytotoxic T cells to target and kill the cells that have become infected with the pathogen and are presenting the antigen
cell mediated immunity
Some viruses may also possess an _______ that surrounds the capsid. The structure is actually a remnant of the _______ cell and not made by the virus.
envelope, host
The primary target of the influenza virus is the
epithelial cells lining the respiratory system.
a line of evidence that provides information on transitional species
fossil record
Component 1, the ________ , contains a relatively small number of genes.
genetic material
the comparison of genetic and biochemical similarities to indicate evolutionary relationships
genetic material
The differences between heritable traits of organisms of a population are known as
genetic variation
Structures that are passed on from a common ancestor, such as the bone structure of a limb, are called ______ structures.
homologous
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
When individuals with favorable traits will survive at a greater rate than those without them, this is an example of
individuals differ in their fitness
When heritable traits such as physical characteristics, physiology, and behavior vary within a population, this is an example of
individuals vary in their traits
- release of chemical signals triggers a series of events to fight off an infection - first immediate action taken by the immune system against an injury
inflammatory response
damaged tissue undergoes a series of events to prevent the spread of a pathogen; symptoms associated with the response are redness, pain, swelling, and heat
inflammatory response
- increase blood flow to the infected area. - isolate the infection to a limited area. - allow fluid, containing cells from the immune system, to reach the infected area.
innate immune system
In some instances, an _______ host, like a pig, allows for the exchange of _________ between two different strains of the influenza virus: an avian influenza strain and a human virus strain.
intermediate, genetic material
- system that transports lymph throughout the body - network of tissues and organs that filter bodily fluids - organ system that connects the circulatory and immune system
lymphatic system
after a vaccine is given, the immune system generates _________________ for the antigen
memory B and T cells
two basic methods by which the flu changes its genetic information
mutations and reassortment
- nonspecific - destroy cells of the body that have been infected by pathogens
natural killer cells
What mechanism did Charles Darwin propose after studying South America and the Galapagos?
natural selection drives evolutionary change; extinct animals resembled the living ones of the same regiond
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
- directly involved in identifying pathogens - some cells phagocytize pathogens - macrophages and dendritic cells
phagocyte cells
- structures and chemicals produced by the body to slow or prevent pathogens from entering the body - skin, stomach, respiratory tract
physical barriers
type of B lymphocytes that are associated with the lymphatic system that secrete antibodies into lymphatic system and identify free pathogens that are circulating throughout the body
plasma B cells
- act as molecular targets that identify pathogens for destruction by the immune system - create holes in the bacterial membrane, destroying the bacterial cell - complement proteins
protective proteins
during the ______, when the immune system is exposed to the same antigen again, the production of antibodies is immediate and is expected to prevent disease symptoms
secondary response
What mechanism did Alfred Russel Wallace propose after studying the South Pacific Islands?
specification; there were similar but distinct species found all over and on similar islands
Antiviral medicines target either the molecules on the surface of the host cell that the virus identifies with, or proteins that the virus uses to attach to the cell
targeting attachment
In the early 1800s, prior to Darwin and Wallace, the common beliefs of the time were..
that species did not change
The set of instructions or genetic material used by living organisms is
DNA
B and T cells are capable of binding to and recognizing specific targets because on their plasma membrane, they have ________
antigen receptors
An example of an antiviral drug, called Tamiflu, inhibits a viral enzyme called ________ to prevent the influenza virus from releasing new viruses from the host cell.
neuraminidase
How does the body recognize "self" cells compared to "nonself" cells?
"Self" cells are marked by glycoproteins called major-histocompatibility complexes (MHCs).
Which protein structures on the SARS-CoV2 virus identify host cells?
S (spike proteins)
vaccines contain an antigen and activate the _______ immune system
adaptive
What is the correct sequence of events in viral reproduction?
Attachment, penetration, biosynthesis, maturation and release
- develop and mature in the bone marrow. - carry receptor molecules on their cell surfaces. - change into plasma cells after encountering an antigen and then produce antibodies.
B cells
Evolution is described as the change in heritable traits of a(n) __________ over a period of time.
population
In living organisms, the flow of information is from
DNA -> RNA -> protein
__________ immunity 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
Over many generations, natural selection leads to __________ , an explanation for the process of how organisms change over time.
evolution
- nonspecific - destroy pathogens by phagocytosis
macrophages, dendritic cells, and neutrophils
Antiviral medicines target the enzyme that interacts with specific molecules in the host cell's membrane to allow the newly formed viruses to escape the host cell.
targeting release
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.
when two different influenza viruses infect the same host cell, and a new form of the virus is manufactured.
antigenic shift
The SARS-CoV 2 virus enters host cells by
attaching to ACE2 receptors.
__________ leads to an evolutionary change due to differential survival and reproduction rates of individuals, because of differences in traits
natural selection
- microscopic protection unit defending cells from foreign objects and pathogens - patrols every organ and tissue in the body - composed of macrophages, dendritic cells, and neutrophils - composed of natural killer cells - composed of B and T lymphocytes
immune system
The influenza vaccine elicits an immune response by presenting the body with
antigens specific to the virus
When a population produces more offspring than can survive, and competition exists among individuals for available resources, this is an example of
individuals struggle to exist
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