(4.1) Communicable diseases

Question 1

What is a pathogen?

Answer 1

A microorganism that causes disease

Question 2

What are the 4 examples of pathogens?

Answer 2

• Bacteria
• Virus
• Fungi
• Protists

Question 3

How are bacteria harmful?

Answer 3

Produces toxins and reproduces through binary fission

Question 4

How does Cholera cause harm?

Answer 4

It’s toxins interfere with chloride ions

Question 5

If the environment is optimum, how fast do bacteria reproduce?

Answer 5

Up to every 20 minutes

Question 6

What type of bacteria is tuberculosis?

Answer 6

Mycobacterium

Question 7

What is a mycobacterium?

Answer 7

A very small bacteria

Question 8

What are 3 examples of diseases caused by bacteria?

Answer 8

• Tuberculosis
• Meningitis
• Ringrot

Question 9

How do viruses cause harm?

Answer 9

Takes over cells and reproduces inside of them

Question 10

How does HIV cause harm?

Answer 10

Targets the nucleus of a cell

Question 11

What are the 2 examples of viruses?

Answer 11

• HIV
• Tobacco Mosaic Virus

Question 12

How do fungi spread?

Answer 12

Hyphae release extracellular enzymes and digest surfaces e.g. skin

Question 13

What is a hyphae?

Answer 13

In fungi and are branching filaments

Question 14

What do many hyphae make?

Answer 14

A mycelium

Question 15

What are the 3 examples of fungi?

Answer 15

• Athlete’s foot
• Black Sigatoka (banana plants)
• Ringworm

Question 16

What are protists?

Answer 16

Complicated, single cell organisms

Question 17

How do protists cause harm?

Answer 17

They enter the cell and feed on its contents

Question 18

What are the 3 examples of protists?

Answer 18

• Malaria
• Potato/Tomato blight
• Sleeping sickness

Question 19

What are the different forms of transmission?

Answer 19

• Direct contact
• Exchange of fluids
• Contamination
• Airborne
• Vector

Question 20

What examples of disease are spread by direct contact?

Answer 20

• Meningitis
• Ringworm
• Athletes foot

Question 21

What is exchange of fluids?

Answer 21

• Sex
• Blood transfusions
• Needles

Question 22

What examples of disease are spread by exchange in fluid?

Answer 22

HIV

Question 23

How does contamination cause disease?

Answer 23

faecal-oral - faeces gets into the body orally e.g. unwashed food

Question 24

What are the 2 different types of airborne transmission?

Answer 24

• Truly
• Droplet

Question 25

What examples of disease are spread by truly airborne transmission?

Answer 25

- Measles - Anthrax

Question 26

What examples of disease are spread by Vectors?

Answer 26

Maleria

Question 27

What is the R value?

Answer 27

The rate of transmission - amount of people you're likely to infect if you have an illness

Question 28

What is the R0 value?

Answer 28

The natural/initial spread of disease without immunity

Question 29

What are the physical/passive plant defences?

Answer 29

- cellulose - waxy cuticles - bark - stomata closing - callose - tyrose

Question 30

What is the role of callose?

Answer 30

A protein that blocks the phloem, specifically the sieve plates

Question 31

What is the role of tylose?

Answer 31

Blocks the xylem

Question 32

When are tylose and callose deposited?

Answer 32

When pathogens are detected

Question 33

How do pathogens normally spread through plants?

Answer 33

Through the vascular tissues

Question 34

What are the chemical defences of a plant?

Answer 34

- terpenoids - phenols - alkaloids - defensins - hydrolytic enzymes

Question 35

What are examples of terpenoids?

Answer 35

Menthols and piney scents

Question 36

What are the primary defences of the human body?

Answer 36

- The skin - Mucous membrane - Ear wax - Tears - Stomach acid

Question 37

How are tears a primary defence?

Answer 37

They contain lysozyme

Question 38

Describe how skin is a primary defence

Answer 38

- contains keratin which makes it impermeable - when cut can clot due to an enzyme cascade

Question 39

What is keratin produced by?

Answer 39

Keritanocytes

Question 40

Describe the enzyme cascade

Answer 40

Collagen is exposed causing an enzyme cascade which turns fibrinogen into fibrin

Question 41

What does -ogen at the end of a molecule mean?

Answer 41

It represents the inactive form of a molecule

Question 42

What is underneath the mucous membrane and why?

Answer 42

- A good supply - surveillance for the specific immune response - Patrolling macrophages

Question 43

Where are mucous membranes?

Answer 43

On exchange surfaces e.g. lungs and digestive system

Question 44

How is mucous produced?

Answer 44

By goblet cells

Question 45

What can the mucous membrane trigger?

Answer 45

Coughing and sneezing

Question 46

What is the role of the ciliated epithelial cells?

Answer 46

Waft pathogens up of the lungs that have been entrapped in mucous and then push it down into the stomach where it is destroyed by the stomach acid

Question 47

How often do ciliated epithelial cells waft?

Answer 47

11-12 times a second

Question 48

What is inflammation?

Answer 48

The direction of blood to infected and damaged areas. This causes vasodilation and moves neutrophils into the tissues.

Question 49

What does inflammation cause?

Answer 49

Secondary responses

Question 50

What are the 2 types of phagocytes?

Answer 50

- Neutrophils - Macrophages

Question 51

What does a neutrophil look like?

Answer 51

Has a multilobed nucleus

Question 52

What does a red blood cell look like?

Answer 52

It is biconcave

Question 53

What does a lymphocyte look like?

Answer 53

It has a large nucleus that nearly completely fills the cell

Question 54

Describe the process of Phagocytosis

Answer 54

- The pathogen binds to either antibodies of through PAMP - The neutrophil engulfs the pathogen - Lysosomes fuse with the pathogen and create a phagolysosome - The Lysosomes digest the pathogen into amino acids and proteins, all good nutrients is absorbed by the cell