My overview of whats important in biology

Natural selection process

1. Individuals vary in their traits. 2. Inidividuals struggle to exist 3. Individuals differ in their fitness and pass the traits down to the next generation 4. Populations become adapted to the environment

What is a mutation

A change in the sequence of nucleotides in the genetic material which can change the sequence of amino acids in a protein and thus the properties of that protein

active immunity

A form of acquired immunity in which the body produces its own antibodies against disease-causing antigens.

Helper T cells

A form of lymphocyte that can recognize the combined MHC-II-antigen receptor on the macrophage. WHen this happens, it is activated and starts to divide, producing cytokines that alert the antibody mediated responses and starts the activation of cytotoxic T cells

Thimersol in flu vaccine

A preservative that may be present in some multi-dose vials of the vaccine

natural selection. Ex:

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits. Giraffe and their neck example

How does the immune system recognize self from nonself?

A series of markers present on the plasma membrane of each cell. The plasma acts as the barrier between the interior of the cell and the exterior environment. The membrane is made of phospholipids adn within are a variety of proteins.

Cytotoxic T cells

A type of lymphocyte that kills infected body cells and cancer cells. Targets the cells of our bodies that hvae been infected by a pathogen and are presenting a specific pathogen on their surface.

Trivalent vaccine

A vaccine that protects against three strains. Contains inactivated (killed) virus particles that cannot reproduce

How do viruses infect cells?

A virus has certain molecules that allow it to attach to a specific kind of cell and the virus then injects its nucleic acid into the cell. For influenza A, it is carried out by the H spike.

What are antiviral medicines?

A way to combat a virus that has the ability to evolve rapidly. either in attachment, when vriuses are specific in the types of cells they infect so it's possible to target either the molecules on teh surface of the host cell that the virus identifies with or the proteins that the virus uses to attch to the cell; Uncoating. Once inside the cell, some viruses provide an enzyme to remove their genetic material from the capsid; Release. Many viruses provide an enzyme that interacts with specific molecules in the host cell's membrane toa llow the newly formed viruses to escape the host cell

How are flu viruses named?

According to their host, type, strain, and year of isolation

Interferon as a chemical signal of the immune response (cytokine)

Acts as a signal to nerby cells that a cell has been infected by a virus

cell-mediated immunity

Adaptive immunity form; lymphocte type of immunity produced by T cells that attack infected or abnormal body cells

Archaeopteryx

An example of a transitional species between reptiles and birds and an example of descent with modification

Tiikalik roseae

An example of descent with modification. Called "fishapod" because it is the transitional link between fish and amphibians

Formation of fossils

An orgainism dies in a marine environment and is covered by sediment, impressions of the softer parts may be made and the hard parts become mineralized fossils

Pathogen

An organism that causes disease

APC

Antigen-presenting cell; a macrophage that has a portion osf an antigen on its surface to alert the remainder of the immune system. The specific stages of the immune system will then target anything in the body that matches the antigen, be it a pthogen encountered int he fluids of the body or a cell that has been infected by the pathogen.

what does evolution tell us about how the influenza virus will change?

Antigenic shift will occur and produce new forms fo the virus that culd infect humans and 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 new viruses. This has the potentail to intrudce new mutations by antigenic drift, which can produce new variants of the H and N spikes. Because our immune system often uses H spikes as an antigen, any change in a virus's structure could create problems at the individual and population level

How are antigens produced?

Antigens are produced when a macrophage engulfs a pathogen. 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 which alerts the remainder of the immune system.

Tamiflu

Antiviral medication that disrupts the influenza virus life cycle by targetting the release stage of influenza life cycle by inhibiting a viral enzyme, called neuraminidase, that allows the virus to leave the host cell. Rapivab and Relenza have similar functions

How does the flu vaccine work?

Associated with active immunity, direct exposure to the pathogen (like influenza virus) prompts an immune response. Fortunately, by exposing an individual to an antigen that is specific to that pathogen but not the actual pathogen itself, the body begins an immyne response to the antigen and in the process generates memory B and t cells. However, when you get th flu vaccine, you don't get the fly virus because its a killed version. H spikes are unique to influenza so it is possible to build vaccinations that use these spikes as antigens and prime the immune system for future exposure tot eh actual virus. When you are exposed to the actual virus, the response of your memory B and T cells, generated during the primary response to the vaccine, is faster and more effective and generally able to protect you from getting the flu

What does the tree of life include?

Bacteria and Archaea, which are both prokaryotic, single-celled organisms, and Eukarya, which is Eukaryotic, single-celled to multicelllular organisms

Jean Babtiste Lamarck

Believed that complex life forms are descended from simpler forms. Inheritance of acquired characteristics.

analogous structures

Body parts that share a common function, but not structure. I.e. wings on birds, bats and insects

Proteins

Built from aino acids, they are the working molecules of the cells

Attachment

Capsid combines with receptor

Evolution

Changes in a species or population over time. Only occurs when heritable changes in the genetic information are passed on from generation to generation.

Cytokine symptoms and action for the Integumentary system

Chills. Restriction of blood vessels in the skin to conserve heat

Nasal Spray

Contains weakened versions of the flu virus and may produce some flu-like symptoms. It is less affective than a trivalent or quadrivalent vaccine

Chemical signals of the immune response are collevtively called ___

Cytokines

What is the genetic material of a virus?

DNA or RNA, it contains the instructions needed to make the proteins that compoase the capsid surrounding the virus and for influenza a, the H and N spikes.

What is the flow of information in all organisms except retroviruses?

DNA to RNA to proteins

Innate defenses

Defenses that act as general defenses and don't target specific pathogens. The first line of defense is the physical barriers which are structures and chemicals produced by several of the organs and tissues of the body that slow or prevent pathogens from entering

Antigenic

Describes organisms that can evade our immune defenses

Natural killer (NK) cells

Destroy cells of the body that have been infected by viruses or bacteria. Nonspecific

Macrophages, dendritic cells and neutrophils

Destroy pathogens (organisms that cause disease) by phagocytosis (surrounding and engulfing it). Nonspecific

What does influenza do that accounts for many flu symptoms

Disrupts the epithelial cells that regulate the activities of the body

antiviral drugs

Drugs that act, are effective, or are directed against viruses.

Aluminum salts in flu vaccine

Enhances the ability of the immune system to detect the virus. Some vaccinations are aluminum free

The Flu and the respiratory system

Enters through mouth or nose. Travels down the pharynx into the trachea and lungs. H spikes identify host epithelial cells. N spikes act to initiate entry of the virus into the target cell. The replication cycle begins immediately. Once inside, the virus hijacks the cellular machinery to make new viruses and produces proteins to interfere with the normal function of the epithelial cell. Fluid accumulation occurs in the lungs. As the epithelial cells lose their function, they may undergo apoptosis/programmed cell death. This may cause inflammation of the tissue which activates the immune system. The immune system sends a host of cells to the respiratory system. Chemical signals increase blood flow to these tissues and combined, this causes tissues to swell and inflammation to increase. As a result, large amounts of mucus are produces, which casues the congestion and cough.

What types of cells does influenza infect?

Epithelial cells lining the respiratory system

Georges cuvier

Father of paleontology

Directional selection

Form of natural selection in which the entire curve moves; occurs when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve

What two components do all viruses have?

Genetic material and a capsid

Interleukin as a chemical signla of the immune response (cytokine)

Glycoprotein that is involved in regulating the general immune response

Types of Spikes on Influenza Virus

H spikes and N spikes

Cytokine symptoms and action for the Nervous system

Headache and fever. Presence of cytokines tells the hypothalamus in the brain to increase the body temperature

H spikes

Hemagglutinin, allows the virus to attach to specific host cell receptors by identifying a specific molecule on the surface of the cell

Embryonic development

Homologus structures are evident during the embryonic development of animals because the embryos look similar. The similarity in embryonic development is due to the action of a series of developmental genes called Hox genes.

How does evlution relate to the influenza virus?

Human influenza viruses originate in animal hosts like the pig and bird. When those two exchange genetic material, they evolve into new forms, which can be transmitted to humans, causing flu outbreaks

Stomach as a physical barrier for pathogens

Hydrocholoric acid (low pH) destroys bacteria and other pathogens

Where did the influenza virus originate?

In prokaryotes

Formaldehyde in flu vaccine

Inactivates any toxins from the viruses or bacteria that may have been present during production

Histamine as a chemical signal of the immune response (cytokine)

Increases the permeability of the capillaries and causes fluid to be released into the area of the wound. Responsible for the symptoms of an allergy

RNA viruses

Influenza A and HIV

Epithelial cells

Involved in regulating the movement of materials into and out of the tissues of the body, such as the respiratory tract and digestive tract. Our skin also is composed of it to isolate us from our external environment

Lymphatic system

Involved in returning fluids (called lymph) from the tissues of the body back to the circulatory system, filtering/cleaning the blood and interstitial fluids of the body, or in the production and maturation of immune system cells called lymphocytes.

alternative pathway of complement activation

It is triggered by the presence of infection but does not involve antibody. The early stages leading to cleavage of C3 involve iC3b, factor B, and factor D.

Cytokine symptoms and action for the Muscular system

Joint and muscle aches. Breakdown of muscle fibers and accumulation of fluid

Cytokine symptoms and action for the digestive system

Loss of appetite, nausea, vomiting. Reduces action of appetite centers in the brain.

What cells are directly involved in identifying pathogens?

Macrophages and dendritic cells

Major-histocompatibility complexes (MHS)

Markers present on the plasma membrane of each cell that helps the immune system recognize self from non self

Alveoli

Millions of tiny air sacs in the lungs where gas exchange occurs. They are thin walled structures lined with a single layer of epithelial cells.

Antigenic drift

Minor change in influenza virus antigens due to gene mutation. May be introduced by the acion of the reverse transcriptase enzyme, is due to minor mutations in the structure of teh H and N spikes and may result in a reduced fidelity for flu vaccines

Chicken Egg method

Most common method: inject the virus into fertilized chicken eggs, allow them to incubate for a few days while the virus begins to replicate. Then extract the liquid portion and kill the viruses in it. The virus particles are then isolated, purified and used to make the vaccines. This requires the longest development time.

Respiratory tract as a physical barrier for pathogens

Mucous membranes trap microbes; they contain chemicals that protect against pathogens; cilia

N spikes

Neuraminidase enzyme, helps break down mucous material surrounding host cells in the respiratory tract and initiates penetration of the virus into the host cell

What research is being done on a universal flu vaccine?

New vaccines are being designed t o use other proteins within the capsid of the virus as the bases for programming the adaptive responses. These proteins, core proteins, don't change at the same rate as the H and N spikes and are more similar between influenza viruses.

Release

New viruses leave host cell

Recombinant process

Newest process, only a small portion of the influenza virus is used. The portion protein of the H spike is used. The protein is added to the virus that infects insect cells and is then cultured to produce large amounts of the H spike protein. The complete virus isn't produced and the extracted H spike protein is used to make the vaccine. This is the most rapid method of producing a vaccine and allows for egg-free vaccines.

Is it possible to have an antibody on reserve for every variant of antigen? Why?

No, each B lymphocyte can produce a single form of antibody, and within are genes that allow for the production of antibodies that vary slightly in their structure and the antigen it will produce. This gives our immune system tremendous felxibility in the types of pathogens it can respond to

Skin as a physical barrier for pathogens

Normal bacteria (flora) on the surface, along with chemicals released by oil and sweat glands, inhibit bacterial growth

What happens if a mutation occurs in the DNA

Nothing, death of the cell or organism, or often the final protein assumes a slightly different shape and the result is variation in that trait.

The immune response

Our immune system has several levels of defenses, from nonspecific phsycial barriers to cellular mechanisms of protecting us from specific pathogens such as the influenza virus

Inflammatory response events

Part of innate defenses. The damaged tissue and nearby immune cells release histamine, causing fluid to leak from nearby capillaries slowing the movement of pathogens and increases blood flow to the area to deliver additional white blood cells (like macrophages) and clotting factors to repair the would. The macrophages identify and destroy any bacteria or viruses int he wound area. Neutrophils remove dead cells, woulnd debris and any pathogens in the area by phagocytosis. If additonal assitance is needed, neutrophils may release cytokines to recruit more immune cells to the area. Clotting factors close off the wound. This causes pressure to build and accounts for the red, tender appearance of inflammation

MHC-I

Present on every nucleated cell of the body. This is the general self identification tag.

Antibiotics in flu vaccine

Prevents bacterial growth during preparation and storage of the vaccine

5 characteristics to determine if something is alive or not

Process energy and materials, maintains an internal environment, responds to stimuli from the environment, reproduces, and adapts to changing environmental conditions

B lymphocytes

Produce antibodies to target specific antigens in the fluids of the body. Specific

Charles Lyell

Proposed that the Earth's surface is dynamic and constantly undergoing erosion and uplift, explining the different fossil layers

Complement proteins

Proteins in blood produced by the immune system that help destroy pathogens by coating or puncturing them. Enhanses inflammation, cell lysis and opsonization. C1-C9

Cytokines

Proteins released by white blood cells that alarm the organ systems of the body that a pathogen is present

Antibodies

Proteins that attach to antigens, keeping them from harming the body. It can clump together around an antigen, inactivating it, or it can bind to the antigen and flag it for destruction from a natural killer cell

The fossil record

Provides us with ideas of what organisms were like in the past and gives an indication of how they have evolved over time

Influenza virus uses ____ to manufacture mRNA molecules directly from the virues's RNA molecules, bypassing the need for a reverse transcriptase

RNA Polymerase

How do viruses evolve?

RNA genetic material in the influenza virus mutates and develops develops methods ot avoid our immune system

What is the flow of information in retroviruses?

RNA is converted into DNA with an enzyme called reverse transcriptatse so it can be processed by the host cell

Egg protein in flu vaccine

Remnants from the production of the vaccine. Newer vaccines that do not use eggs during production won't have these proteins present

Immune system

Responsibel for protecting our bodies from foreign pathogens like viruses and bacteria, and works closely with the lymphatic system

Cell-based method

Similar to the process with chicken eggs, except the viruses are placed into mammalian cell cultures to replicate.

MHC-II

Special identification tag. Molecules only found found on macrophages, B cells, and activated T cells that signal helper T cells. Alerts the immune system of specific pathogens.

Gelatin, sorbitol or monosodium gluamate (MSG) in flu vaccine

Stabalize the vaccine and protect it from temperature variations during storage

Thomas Malthus

Stated that populations sometimes increase at rates fater than their food supply can increase, creating competition

homologous structures

Structures in different species that are similar because of common ancestry. I.e. limbs of a mouse, bat and whale

T lymphocytes

Target cells that have been infected by a specific pathogen. Specific. White blood cells produced in thebone marrow. After being formed, they travel to the thymus where they mature. As they mature, each develops receptors that will allow it to recognize a single form of antigen.

What are the methods of producing a flu vaccine?

The Chicken Egg method, Mammalian Cell-Based method, and Recombinant method

Evidence of evolution is biology

The Fossil Record, Comparative anatomy, Embryonic development and genetic material

What are most flu symptoms a result of?

The activation of the immune system and chemical signals released in resonse to infection. The white blood cells release proteins called Cytokines which acts as an alarm to the organ systems of the body

Memory

The adaptive immune response ability to remember past exposures to pathogen. Some activated B cells are held in reserve and not used in the first response to teh antigen and wait for future exposure. This is useful if you come into contact again.

Genetic Comparisons

The closer the genetic information is between two species, the closer their evolutionary relationship

Comparative anatomy

The comparison of body structures and how they vary among species. Homologous structure.

What happens when influenza enters an epithelial cell ont eh surface of our respiratory tract?

The infected cell posts an antigen on its surface, attached to a MHC-I marker, flagging cytotoxic T cells that were just activated by the helper T cells. The cytotoxic T cell then attaches to the target cell and releases a protein called perforin, which opens a hole in the membrane. Granzymes enter the hose, casing the cell to undergo programmed cell death/apoptosis.

Thymus

The organ where T lymphocytes mature

Spleen

The organ where blood is filtered and cleaned by the action of white blood macrophages

How are flu viruses selected to make a vaccine?

The process begins a year in advance. Over 100 worldwide monitering stations send clinical samples to influenza centers in 5 countries. There, scientists review data to determine each flu virus's potential to cause a world-wide pandemic, what is known about the strain of the virus, and the ability to produce an effective vaccine against the strain.

What introduces mistakes that can cause variation in new viruses

The use of reverse transcriptase enzymes or RNA polymerase

How do animals play a role in virus evolution?

They cause antigenic shift when the virus combines inside thier cell (bird virus and human virus combining inside a pig cell)

Immune system and lymphatic system

They work closely to protect the body from pathogens. The immune system monitors the fluids from the lymphatic system for the presence of pathogens through the lymp nodes of the body. At those times when you're sick, you may feel warmth and pain from your lymph nodes as the cells of the immune system engage the pathogens

Erasmus Darwin

Thought all living things came from a common ancestor

How does the flu enter the body?

Through the mouth or nose, often from touching something where the virus is. From here it enters into the respiratory system and travels down the pharynx into the trachea and lungs.

Lymph nodes

Tissue where the interstitial fluid is filtered and cleansed by white blood cells called macrophages

red bone marrow

Tissue where the lymphocyte cells of the body are produced. The location where B lymphocytes mature

Types of flu vaccines

Trivalent, quadrivalent, and nasal spray

Antigenic shift

Two different influenza viruses infect the same host cell so a new form of the virus is made, formation of new combinations of H and N spikes on the virus, and a slower adaption by the immune system

Evolution is recognizes as one of the _____ of biology. That means that ____

Unifying theories; almost every aspect of the biological sciences may be explained by evolutionary processes and plays a role in all levels of biology.

B cell

Unlike a T cell, a B lymphocyte can bind directly to an antigen, even if it is still ont he surface of the pathogen. If a B cell recognizes the influenza virus directly it can start to produce antibodies against it. this is known as adaptive immunity.

Penetration

Viral DNA enters host

Maturation

Viral components are assembled

Retrovirus

Virus that contains RNA and uses the enzyme called reverse transcriptase to make a DNA copy

Antibody-mediated immunity

While helper T cells andcytotoxic T cells are working to target infected cells, teh B lymphocytes begin the production of antibodies.

Quadrivalent vaccine

Works by stimulating an immune response against four different antigens. Contains inactivated (killed) virus particles that cannot reproduce

inflammation

a localized response to an injury or to the destruction of tissues

Life cycle of a virus

attachment, penetration, biosynthesis, maturation and release

Opsonization

coating antigen with antibody enhances phagocytosis

classical pathway of complement activation

complement binds to an antibody that is bound to a foreign substance.

Fidelity

faithfulness; loyalty

Lysogenic cycle

following penetration, the DNA integrates into the cell's DNA and remains inactive. As the host cell divides, it divides. It remains latent until some environmental factor signals it to reenter the lytic cycle.

Disruptive selection

form of natural selection in which a single curve splits into two; occurs when individuals at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle

Stabilization selection

most common form of natural selection in which organisms with extreme expressions of a trait are removed

Macrophages

phagocytize foreign substances and help activate T cells

Phagocytosis

process in which extensions of cytoplasm surround and engulf large particles and take them into the cell

Glycoprotein

protein witha large sugar group attached, acts as identification tags

Transitional follis

represent intermediate forms, are an excellent example of descent with modification, help us understand how species have changed over time, and provide an indication of the timeline of these changes

Cell lysis

rupturing membranes of foreign cells

Antigen

substance that triggers an immune response. Usually proteins or large carbohydrates that are specific to pathogens like bacteria and viruses.

adaptive immunity

targets specific antigens associated with a pathogen and remembers past responses. able to target cells of the body that are infected with the pathogen while also responding to any pathogens that are free in the blood or interstitial fluid of the body. Must be activated to respond to a specific antigen

What accounts for the types of host species?

variations of the types of H spikes on an influenza A virus

Biosynthesis

viral components are synthesized