Infectious Disease

Question 1

Infectious Disease

Answer 1

Diseases caused by pathogens (e.g. common cold).

Question 2

Non-infectious Disease

Answer 2

Diseases caused by lifestyle, environmental or genetic factors (e.g. diabetes).

Question 3

Contagious

Answer 3

The ability to spread from person to person.

Question 4

Pathogen

Answer 4

Microbes able to cause disease.

Question 5

Prions

Answer 5

Misfolded proteins able to trigger healthy proteins to misfold abnormally leading to brain damage (e.g. CJD)

Question 6

Viruses

Answer 6

Genetic material surrounded by a coat of protein which requires the presence of a host cell to reproduce causing cell death (e.g. COVID-19).

Question 7

Bacteria

Answer 7

Prokaryotic microorganisms which reproduce through binary fission and releases toxins causing tissue damage (e.g. Salmonella).

Question 8

Fungi

Answer 8

Microorganisms which feed at the expense of a host organism and reproduce asexually by releasing spores that cause disease (e.g. Athlete’s foot).

Question 9

Protists

Answer 9

Parasites which spread via vectors and enter the body causing disease (e.g. Malaria).

Question 10

Disease Transmission

Answer 10

Direct Touch

Bodily Fluids

Airborne Particles

Contaminated Ingestion

Vectors

Medical Procedures

Question 11

Adherence Factors

Answer 11

Enables pathogens to adhere to host cells (e.g. bacterial adhesins).

Question 12

Invasion Factors

Answer 12

Enables pathogens to enter host cells (e.g. bacterial exoenzymes).

Question 13

Capsules

Answer 13

Enables pathogens to avoid detection by the immune system (e.g. bacterial capsules).

Question 14

Toxins

Answer 14

Enables pathogens to produce symptoms of disease within a host cell (e.g. bacterial toxins).

Question 15

Lifecycle Changes

Answer 15

Enables pathogens to transmit between various host cells (e.g. blood flukes).

Question 16

Innate Immune Response

Answer 16

Non-specific immune response present in all plants and animals to protect against pathogens by reducing the likelihood of disease and controlling the severity.

Question 17

First Line of Defence

Answer 17

A system of barriers to prevent pathogens from entering the body.

Question 18

Physical Barriers

Answer 18

Stops pathogens from entering the body by blocking or trapping them (e.g. skin).

Question 19

Chemical Barriers

Answer 19

Kills pathogens before they can enter the body (e.g. stomach acid).

Question 20

Second Line of Defence

Answer 20

A system of generalized responses to pathogens entering the body.

Question 21

Inflammation

Answer 21

The accumulation of fluid, plasma proteins and leukocytes when tissue is damaged or infected.

Question 22

Inflammation Response

Answer 22

Histamines are released from mast cells

Cytokines are released from injured cells

Vasodilation and increased permeability of blood vessels occur due to histamines

Neutrophils migrate towards the cytokines to kill pathogens

Phagocytes (macrophages) phagocytose pathogens and debris

Question 23

Prostaglandin

Answer 23

A type of cytokine that increases the temperature of the body resulting in a fever.

Question 24

Complement System

Answer 24

Proteins which circulate the blood inactively and are triggered to help kill pathogens.

Question 25

Adaptive Immune System

Answer 25

Specific immune system which targets specific pathogens by recognizing and memorizing specific antigens and producing specific antibodies through humoral and cell-mediated immunity.

Question 26

Humoral Immune Response

Answer 26

B-cells target pathogens in the body's fluids by producing antibodies from plasma/effector cells which hunt and fight antigens through proliferation alongside memory B-cells which keep samples of the antigen to enhance immunity.

Question 27

Role of Antibodies

Answer 27

Enhances phagocytosis through precipitation of dissolved antigens Prevents adherence through neutralization and agglutination Activates the complement system which leads to lysis of foreign cells

Question 28

Cell-Mediated Immune Response

Answer 28

T-cells target pathogens in the body's cells by helper T-cells recognizing antigens from antigen-presenting cell's major histocompatibility complexes (e.g. macrophages/dendritic cells) utilizing their receptors and proliferating into memory T-cells and activating cytotoxic T-cells.

Question 29

Cytotoxic T-cells

Answer 29

Proliferates into memory cytotoxic T-cells and destroys infected or defective cells by releasing cytotoxins which cause apoptosis.

Question 30

Helper T-cells

Answer 30

Proliferates to create memory T-cells, activates B-cells and cytotoxic T-cells.

Question 31

Passive Immunity

Answer 31

Antibodies are transferred from one organism to another. Lasts for a short time. Natural: Placenta Artificial: Antiserum

Question 32

Active Immunity

Answer 32

Production of antibodies following exposure to antigens. Lasts for a long time. Natural: Disease Artificial: Vaccination