Immunity

Question 1

Explain how a single gene can produce many different proteins.

Answer 1

Post-transcriptional modifications to the transcribed pre-mRNA through alternative splicing can produce many different strands of mature mRNA, leading to the production of many different proteins.

Question 1

disease

Answer 1

Disease refers to the impaired functioning of cells or processes within the body.

Question 2

Explain the difference between the patterns of growth of bacteria and viruses after infection.

Answer 2

After the accumulation of viruses inside a cell and the weakening of the cell’s cytoskeleton, the cell bursts, releasing the viral particles into the extracellular environment. Therefore, every time viruses burst from cells, there is a sudden increase in the number of extracellular viruses.Conversely, bacteria are able to continuously replicate in the extracellular environment, resulting in a smooth exponential curve.

Question 3

State the two role of antigen-presenting cells in the innate immune system.

Answer 3

Antigen-presenting cells phagocytose pathogens/foreign material
present antigens on their surface to specific cells of the adaptive immune system.

Question 4

describe two possible chemicals of the innate immune systems that scientists could expect to find in the milk.

Answer 4

Complement proteins, which are involved in the chemotaxis and opsonisation of pathogens, and cytokines, which are involved in communication between cells of the immune system.
Lysozymes, which can degrade pathogens.
Interferons, which increase resistance to viral infection.

Question 4

Explain 4 ways antibodies interact with antibodies

Answer 4

neutralisation- blocks sites of pathogens used to attack host cells

agglutination- the formation of large antigen-antibody complexes to facilitate phagocytosis

opsonisation- binds to the surface of pathogens to make it easier to phagocytose.

immobilisation-restricts the movement of pathogens

Question 5

Compare the innate and adaptive immune responses.

Answer 5

When comparing the innate and adaptive immune responses, the innate immune response provides the body with a form of non-specific and immediate protection,whereas the adaptive immune response provides the body with a form of pathogen-specific but slow protection

Question 6

Purpose of anitgens

Answer 6

The immune system uses antigens to recognise if a cell or molecule is self or non-self. If it
is identified as non-self, an immune response is initiated.

Question 7

Self-antigens

Answer 7

Self-antigens, which are located on the surface of cells, mark the cells of an organism as
‘self’ so that the immune system doesn’t attack them. In vertebrates, the most important
self-antigens take the form of major histocompatibility complex (MHC) markers,
which can be divided into two different classes:
* MHC Class I markers are expressed on all nucleated cells in the body. Therefore,
virtually all cells in the human body except for those without a nucleus (e.g. red blood
cells) express MHC Class I markers.
* MHC Class II markers are found on specialised cells of the immune system

Question 8

antigen

Answer 8

any molecule that may
trigger an immune response

Question 9

pathogen 

Answer 9

an agent that causes
disease

Question 10

non self antigen

Answer 10

Non-self antigens are antigens that the immune system reads as ‘foreign’ or not belonging to that individual. If a non-self antigen is recognised within the body, the immune system is activated and attempts to eliminate it

Question 11

autoimmune disease

Answer 11

a disease in which an individual’s immune
system initiates an immune response against their own cells

Question 12

outline 2 malfunctions related to immune system

Answer 12

1.One type of malfunction involving antigens can occur when an error in the immune system results in the recognition of self-antigens as non-self. This results in the immune
system attacking self-cells and is known as an autoimmune disease.(eg.rheumatoid arthritis and lupus)
2.Allergies involve an overreaction to the presence of an allergen . Allergens are antigens that the
immune system recognises as non-self and initiates a strong immune response towards.However allergns dont cause harm at all.

Question 13

How do IgE antibodies play a role in allergic response?

Answer 13

1)Allergen Exposure: When a person with allergies comes into contact with an allergen, their immune system produces IgE antibodies specific to that allergen
2)IgE Binding: These IgE antibodies attach to the surface of mast cells and basophils, which are immune cells found in tissues throughout the body.
3)Release of Histamine: This binding triggers the release of histamine and other inflammatory chemicals from these cells.

Allergic Symptoms: The release of these chemicals causes the typical symptoms of an allergic reaction, such as sneezing, itching, runny nose, watery eyes, and in severe cases, difficulty breathing or anaphylaxis

Question 14

Cellular pathogen vs. non-cellular pathogens

Answer 14

have a cellular structure and are living organisms

Question 14

Bacteria

Answer 14

Unicellular prokaryotes that can infect almost
any part of the body. Bacteria can cause disease
through the production of toxins and enzymes
which either affect the functioning of cells or cause their death.Reproduce through binary fission.

Question 15

Fungi

Answer 15

Eukaryotic organisms that include yeasts and
moulds and contain long, branching filaments
called hyphae.
Fungi reproduce both through
aesexual reproduction and sexual
reproduction via spore formation.

Question 16

Worms

Answer 16

Multicellular invertebrate parasites whose
development include egg, larval, and adult stages.
Can vary in length, with the longest worms being
over 55 m in length.
Worms reproduce sex

Question 17

Protozoa

Answer 17

Single-celled eukaryotes that can be free-living
or parasitic. Protozoa have many different
mechanisms of action – for example, some can
inhibit nucleic acid synthesis, protein synthesis,
and various stages of cellular respiration.

Question 18

Viruses

Answer 18

An infectious agent composed of genetic material
(DNA or RNA) inside a protein coat (capsid). In
some instances the protein coat is surrounded by a
lipid envelope. Viruses are not able to independently
reproduce, instead they insert their genetic material
into a host’s cell and use the cell to replicate.
Viruses can cause disease through the lysis of cells
during viral replication, the formation of cancer by
affecting gene expression, and the over-stimulation
of the immune system leading to organ damage.

Question 19

What kind of cell have MHC II on their surface, and how they help the apadtive and immune system?

Answer 19

This cell is an antigen-presenting cell.(marcophages, dendritic cells, B cells) .MHC II allows the cell to present digested foreign antigens on its surface and interact with T and B cells to stimulate the adaptive immune response.

Question 20

One type of phagocytic cell is not involved in the activation of the adaptive immune response.

Identify this cell type, and explain why it is not involved in activating the adaptive immune response.

Answer 20

Neutrophils are a phagocytic cell which are not involved in the initiation of the adaptive immune response.Because they are not antigen-presenting cells and do not express MHC II, they cannot interact with T and B cells.

Question 21

what is a control group

Answer 21

Acts as a base-line of comparsion, and shows what results are obtained when the independent variable is not in affect, to see what true effect does the independt variable.

Question 22

Explain one mechanism by which the antibodies prevent the clumping of red blood cells.

Answer 22

The antibodies form antigen-antibody complexes, immobilising the virus particles.

Question 23

describe the lymphatic system

Answer 23

The lymphatic system is responsible for the transportation of Antigen presenting cells to lymph nodesfor antigen recognition and the production of leukocytes. Additionally, while both B and T cells are produced in the bome marrow, B cells mature in the bone marrow and T cells mature in the thymus.

Question 24

primary lymphoid tissue

Answer 24

Primary lymphoid tissues are responsible for the creation and maturation of lymphocytes. The main primary lymphoid tissues include the bone marrow and the thymus.Both B and T lymphocytes are produced in the bone marrow, however B cells mature in the bome marrow and T cells mature in the thymus.

Question 25

Secondary lymphoid tissues

Answer 25

Secondary lymphoid tissues are responsible for maintaining mature lymphocytes and
initiating the adaptive immune response. The main secondary lymphoid tissues include
the lymph nodes (e.g. tonsils) and the spleen.

Question 26

lymphatic capillaries

Answer 26

 the smallest
form of lymphatic vessel. Located
in the spaces between cells

Question 27

afferent lymphatic vessel

Answer 27

thin-walled structures that collect lymph from the tissues of the body and deliver it to lymph nodes

Question 28

afferent lymphatic vessels

Answer 28

thin-walled structures that collect lymph from the tissues of the body and deliver it to lymph nodes

Question 29

efferent lymphatic vessels 

Answer 29

thin-walled structures that collect lymph that has drained through lymph nodes, returning it back to
circulation

Question 30

Describe the relationship between between lymphatic flow and Lymphatic surveillance

Answer 30

Lymphatic drainage
Fluid from blood vessels constantly leaks into the tissues of the body.
you should recall that this leakage is increased during an inflammatory response to allow for the movement of leukocytes into tissues.
As the fluid collects containing waste and leucytes between tissue it can cause swelling, however lymphtic system allows for the drainage of the fliud to the mylph nodes and then into then returned into circultation to the heart via effert lympahtic vessels which merge into large vein returing blood to the heart.

Question 31

Explain the role of lymph nodes in the lymphatic system.

Answer 31

Lymph nodes contain mature lymphocytes and are the sites for antigen recognition by T and B lymphocytes, which leads to the initiation of the adaptive immune response via clonal selection and lymphocyte differentiation

Question 32

Explain the delay seen in the activation of the adaptive immune response.

Answer 32

Due to the lengthy transportation of the antigen-presenting cell to the lymph nodes, where it must interact with the complementary receptor on a helper T cell, there is a delay in the activation of the adaptive immune system.

Question 33

disease

Answer 33

disrupt the normal functioning of cells

Question 34

Describe two roles of the lymphatic system.

Answer 34

Firstly, the lymphatic system serves as the means of transport for the pathogen and antigen-presenting cells to the lymph nodes.Secondly, once lymph arrives at the lymph node, the lymphatic system is the site of selection, cloning, and differentiation

Question 35

infectious disease and non-infectious disease

Answer 35

an illness
caused by a pathogen and an illness
not caused by a pathogen

Question 36

zoonosis

Answer 36

An infectious disease caused by a pathogen that has transferred from an animal to a human.

Question 37

Identify 4 factors that led to Australia’s Indigenous population being highly susceptible to the diseases brought by Europeans.

Answer 37

A lack of prior immunity to European diseases and a forced change in lifestyle that decreased their general health status
A lack of knowledge and experience with European diseases.
Being forced to live in densely populated areas.

Question 38

Explain the difference between activation and suppression immunotherapies.

Answer 38

Activation immunotherapies enhance the functioning of the immune system, whereas suppression immunotherapies reduce it

Question 39

functions of monoclonal antibodies

Answer 39

Antibody-dependent cell-mediated cytotoxicity (ADCC)-Monoclonal antibodies bind to cancer cells and interact with cells of the immune system,
particularly natural killer cells (NK cells), causing them to recognise the antibody-coated
cancer cell as foreign and kill it.

complement activation-bind to cancer cell and interact with complemet proteins
check point inhibitiong
trigger cell wall destruction and apoptosis
cytokines inhibition-. Monoclonal antibodies that bind to and inhibit cytokines can
be used to reduce the immune response
* B cell and T cell depletion and inhibition – Monoclonal antibodies that bind to
autoreactive B and T cells can be used to either inhibit these cells or stimulate other
immune cells to destroy them.

Question 39

autoimmune disorder

Answer 39

An autoimmune disorder is when the body’s immune system initiates an immune response that targets healthy self cells.

Question 40

inflammation response outline

Answer 40

Initiation-In response to this injury, macrophages situated in the tissue become activated and, along with damaged cells,
release cytokines. Additionally, mast cells degranulate, releasing histamine.
Vasodilation-histamine would be released by the mast cells, causing vasodilation, which caused increased blood flow (heat and redness) and widdening of the blood vessels, which increased vesel permeability.Swelling is due to increased fluid and flood entering the site of infection and large amount of debris.
Migration:Vasodilation and the increased leakiness of blood vessels allow for a number of innate
immune system components to leave the bloodstream and enter the site of injury, includes phagocytes and complement proteints.

Question 41

vaccine

Answer 41

A vaccine is a medical intervention that contains pathogenic antigens, such as an inactivated component or a weakened form of a pathogen,which triggers the production of antibodies and memory cells, but does not cause disease

Question 42

methods of identifying pathogens

Answer 42

1)physical-using microscope to determine structure

2)Phenotype-using selective media, which is an agar plate that includes nutriets/conditions that only allow certain pathogens to grow.This can help understand certain properties of the bacteria.
3)immunological-the diagnosis of disease based on the presence of antibodies or antigens
in a person’s serum.ELISA can be done to better identify the pathogen with the antibody.
4)Molecular-hybridisation based detection-using segments of the DNA which is complemtary to a pathogen’s genetic material.Segement will glow/send a singnal it is binds.
Whole-genome sequencing – provides detailed information about the pathogen

Question 43

factors that contribute to emergence/re-emergence of a disease

Answer 43

Evolution of pathogen
Globalisation+travel
Increase exposure to animals
Increasing population
Changing technology
Insuffiecent vaccination of population

Question 44

Immunotherapy

Answer 44

the prevention or the treatment of diseases with substances the amplify or supress through the modulating of the immune response

Question 45

controlling of the disease

Answer 45

prevention-hygine,sterille,lockdown,educte
screening-social media reasearches,waste waster,observe sales.
Quarantine
Identify pathogen and mode of transmission
Treat individuals

Question 46

monoclonal antibodies

Answer 46

are specific to one spefic antigen and produced in lab

Question 47

mode of transmission

Answer 47

airborne
droplet
Direct contact
indireact contact
Feacal-oral

Question 48

Purpose of physical barrier and examples.

Answer 48

Purpose of physical barrier and examples.

Intact skin-Intact skin is a protective barrier that constantly renews itself from within. Old skin cells are pushed to the surface, where they eventually flake off as tiny particles.
Mucous membrane:Mucus effectively traps bacteria, viruses, and other microorganisms, preventing them from reaching deeper tissue and adhering on the tissue and cell.
PLANTSSSS
Bark: acts as physical barrier and protects against mechanical damage.
Stomata:Pores allow gas exchange but also a entry point for pathogens, in protecting they keep it close

Question 49

Chemical barrier

Answer 49

Act to inhibit the growth or development of pathogens and act to destroy pathogens.
Skin ph 5.5-may be too acidic for some substance.
Lysozymes:has bactericidal
Gastric acid: ph 1-3,creat hostile environment that pathogens struggle to thrive, can cause the denaturation of proteins.
PLANTSSS
Phenolics:They have antimicrobial and antifungal properties
Oxidative burst:plants can release reactive oxidative species such as hydrogen peroxide that are toxic to the pathogen.

Question 50

Microbiota

Answer 50

prevent the growth or colonization of pathogens, as they consume the nutrients and occupying space. Gut microbiota. Some even produce b12 and vitamin k.