U4 AOS 1

Question 1

Pathogen

Answer 1

An agent that causes disease.

Question 2

Cellular Pathogen

Answer 2

Have a cellular structure and are living organisms

Question 3

Cellular Pathogen - Bacteria

Answer 3

Unicellular Pathogen that can cause disease through toxin and enzyme production to alter cell functioning.

Question 4

Non Cellular Pathogens

Answer 4

Do not have a cellular structure and are non-living.

Question 5

Non Cellular Viruses

Answer 5

An infectious agent composed of genetic material inside a protein that can not independently reproduce.

Question 6

Disease Control Methods

Answer 6

Prevention:practising personal hygiene, drinking clean water, using condoms and bug spray

Vaccination: to provide long-term protection against infectious diseases

Medication: to manage infectious diseases, e.g, antibiotics for a bacterial infection

Surveillance: Monitor disease to prevent outbreaks

Modification: make environment less suitable for microbe growth

Infection Control: prevent spread. Sterilisation,isolation, and hygiene.

Question 7

Disease

Answer 7

A condition that impairs the normal functioning of an organ,structure, or system

Question 8

Infectious disease

Answer 8

Can be transmitted from one person to another

Eg. Cholera

Caused by pathogenic agents.

Question 9

Non- Infectious disease

Answer 9

Can not be spread from affected person via the environment

Eg. Cancer

Question 10

Emerging Disease

Answer 10

Disease caused by an unknown agent that has spread to humans from another species

Question 11

Re-Emerging disease

Answer 11

Reappears after a decline in incidence

Question 12

Endemic Disease

Answer 12

Constantly in low levels in the population

Question 13

Outbreak

Answer 13

Sudden disease increase locally

Question 14

Epidemic

Answer 14

Infectious disease spreads across nation

Question 15

Pandemic

Answer 15

Disease spreads across the world in 3 countries in 2 regions

Question 16

Triad model of infection

Answer 16

Pathogen; the disease causing organism

Host; target of the disease

Environment; conditions that allow transmission.

Question 17

Physical method to identify virus

Answer 17

Identify vurus based on size and shape.

X-ray crystallography; determines structure

Electron microscopy; determines image to identify.

Question 18

Immunological Methods

Answer 18

Detects Antigens or antibodies

(ELISA) enzyme-linked immosorbent aasay.

A. Direct Elisa.
B. Indirect Elisa.
C. Sandwich Elisa.

Question 19

Direct Elisa

Answer 19

• a viral antigen is ppaces on a surface.
• Matching primary antibodies bind to this antigen.
• The primary antigens have an enzyme indicator.

Steps
1. Coat plate with antigen
2. Antibody specific to antigen is added to wells
3. During incubation, antibodies bind to antigen
4. Wells washed to remove unbinded antibodies
5. Enzyme substrate added to test positive

Question 20

Indirect Elisa

Answer 20

Primary antibodies do not have an enzyme indicator

Instead: The enzyme indicator is attached to a secondary antibody… This helps to amplify signal.

Question 21

Sandwich ELIZA

Answer 21

Antibodies bind to the surface

Question 22

Phenotypic Methods

Answer 22

Techniques that involve identifying traits or features

Question 23

Genotypic + Molecular methods

Answer 23

Examines genetic material to identify

Question 24

Patient Zero

Answer 24

The 1st person to contract disease.

Important as; helps to identify how a pathogen can be spread and what organisms can spread

Question 25

Reserviours and Hosts

Answer 25

Transmission occurs when a pathogen leaves hosts and is transmitted to another. Reservoir: the habits in which a pathogen lives,grows, and multiplies Host: infected person

Question 26

Direct Transmission

Answer 26

Person to person contact

Question 27

Indirect Transmission

Answer 27

Airborne or contaminated objects

Question 28

Vectors

Answer 28

Carry pathogenetic agents and spread them. Ticks, fleas, etc.

Question 29

Incubation Period

Answer 29

The interval between exposure and onset. During this: the disease- causing agent multiplies to make symptoms.

Question 30

Asymptomatic Carriers

Answer 30

Infected but does not show sign or symptoms

Question 31

Subunit Vaccine

Answer 31

Contains part of a micro-organism to produce an immune response

Question 32

Whole-Agent

Answer 32

Contains whole non-virulent micro-organism

Question 33

Live Attenutated Vaccines

Answer 33

Weakened live microbe created in a lab, using repeated culturing **Advantages** - single dose has long lasting effects **Disadvantages** - can harm foetuses - can cause disease in a weak immune system

Question 34

Inactivated Vaccines

Answer 34

Contains microbes that have been inactivated by heat or radiation **Advantage**; can be used in people with weak immune systems **Disadvantage** - stimulates a weak immune system - requires boosters to maintain

Question 35

Sub-Unit Vaccine

Answer 35

Labgrown pathogen with chemically extracted antigens **Advantages**; safe, stable, easy to store **Disadvantages**; requires multiple doses

Question 36

Toxoid Vaccines

Answer 36

A type of recombinant subunit vaccine that uses toxins inactivated by formalin to stimulate adaptive immunity

Question 37

Why are Vaccines given:

Answer 37

To reduce spread and build immunity Graph.

Question 38

Monoclonal Antibodies

Answer 38

Artificially produced antibodies that bind to one type of antigen STEPS: 1) Injects mouse with antigen X to make B cells and antibodies 2) repeat injections to increase concentration 3) Remove spleen + culture to separate cells 4) b cells form + fuse with tumor cells = hybridomas 5) unfused cells die leaving only hybridomas 6) hybridomas are cultured in a medium to divide repeatedly 7) cells are checked for antibody presence 8) antigen x harvested 9) injected into subject

Question 39

Natural Immunity

Answer 39

Occurs through contact with a disease causing agent

Question 40

Artificial immunity

Answer 40

Occurs due to intentional exposure and intervention

Question 41

Ways to control pathogen spread

Answer 41

Sterilisation and chemical agents such as antiseptic and disinfectant

Question 42

Inflamation

Answer 42

2nd line of defence **Steps** Initiation: bacteria breeches 1st line of defence (intact skin) Migration: - cytokines are released and attract neutrophils - Fluid with peptides and proteins enters tissue Resolution: - platelets with clotting factors are released - neutrophils kill invading antigen.