4.1 - Communicable Disease, Prevention And The Immune System

Question 1

What is a disease?

Answer 1

It is a condition that impairs the normal function of an organism

Question 2

What is a pathogen?

Answer 2

An organism that can cause disease

Question 3

What are the 4 types of pathogens?

Answer 3

Bacteria, viruses, fungi, protist

Question 4

What is a communicable disease?

Answer 4

A disease that is able to spread between organisms

Question 5

What pathogen causes tuberculosis?

Answer 5

Bacterium

Question 6

What pathogen causes bacterial meningitis?

Answer 6

Bacterium

Question 7

What causes ring rot?

Answer 7

Bacterium

Question 8

What causes HIV/AIDS?

Answer 8

Virus

Question 9

What causes influenza?

Answer 9

Virus

Question 10

What causes tobacco mosaic virus?

Answer 10

Virus

Question 11

What causes black sigatoka?

Answer 11

Fungus

Question 12

What causes ringworm?

Answer 12

Fungus

Question 13

What causes athletes foot?

Answer 13

Fungus

Question 14

What causes tomato/potato late blight?

Answer 14

Protist

Question 15

What causes malaria?

Answer 15

Protist

Question 16

What are the 7 diseases that affect humans and animals?

Answer 16

• tuberculosis
• bacterial meningitis
• HIV and AIDS
• influenza
• ringworm
• athletes foot
• malaria

Question 17

What are the 4 diseases that affect plants?

Answer 17

• ring rot
• tobacco mosaic virus
• black sigatoka
• late blight

Question 18

What are the 2 ways that a disease can be transmitted?

Answer 18

Directly and indirectly

Question 19

What is direct transmition?

Answer 19

When the disease is transmitted directly from one organism to another

Question 20

What are 3 ways that disease can be directly transmitted?

Answer 20

• droplet infection
• sexual intercourse
• touching

Question 21

What is indirect transition?

Answer 21

When a disease is transmitted from one organism to another via an intermediate

Question 22

What are 4 ways that a disease can be indirectly transmitted?

Answer 22

• air
• water
  -food
• vector

Question 23

How can overcrowding affect disease transmission?

Answer 23

TB is spread by droplet infection and can also be spread indirectly because the bacteria can remain in the air for long periods of time and when there is an increased amount of people there will be higher infection rates

Question 24

How can the climate affect disease transmission?

Answer 24

Malaria is more common in tropical countries which are hot and humid, this is because these are ideal conditions for mosquitoes to breed

Question 25

How do social factors affect disease transmission?

Answer 25

Transmission rates are higher in areas that have limited access to good healthcare and good healthcare education

Question 26

What are the 7 primary defences that humans and animals have?

Answer 26

- skin - mucous membranes - blood clotting - inflammation - eyes - ears - expensive reflexes

Question 27

How does the skin work as a primary defence against disease?

Answer 27

It acts as a physical barrier blocking pathogens from entering the body. It can also acts as a chemical barrier by producing chemicals that anti microbial and can inhibit the growth of pathogens

Question 28

How does a mucus membrane act as a primary defence against disease?

Answer 28

They protect the body openings that are exposed to the environment, by the membranes secreting mucus to trap pathogens

Question 29

How does blood clotting act as a primary defence against pathogens?

Answer 29

Blood clots plug wounds to prevent pathogen entry and blood loss

Question 30

How does expulsive reflexes act as a primary defence against disease?

Answer 30

Coughing and sneezing is caused by irritation in the respiring tract or the mucus membranes, this then expels the pathogen

Question 31

How does the eyes act as a primary defence against disease?

Answer 31

Tears are composed of water, salt, antibodies and lysosomes and the lysosomes destroy the microorganisms by breaking down the cell walls so that they can’t reproduce

Question 32

How do the ears act as a primary defence against disease?

Answer 32

The ear canal is lined with ear wax to trap foreign pathogens

Question 33

Define the term passive defence?

Answer 33

A defence mechanism that is present at all times

Question 34

Define the term active defence?

Answer 34

A defence that occurs when a pathogen is detected

Question 35

What are the 2 types of active defences that a plant has?

Answer 35

Physical and chemical

Question 36

How is the waxy cuticle work as a physical defence?

Answer 36

It is a physical barrier that stop pathogens entering and water which may be carrying pathogens

Question 37

How does the cell wall in a plant work as a physical defence?

Answer 37

It acts as a barrier against pathogens if they were to get past the waxy cuticle

Question 38

How does callose act as a physical barrier in plants?

Answer 38

It is a polysaccharide that is deposited between plant walls and the membrane during times of stress so it is harder for pathogens to enter and limits the spread of viruses by block the plasmodesmarta

Question 39

How do anti microbial chemicals work in plants as a chemical defence?

Answer 39

They either kill the pathogens or inhibit them. Saponins destroy the cell membrane of fungi and phytoalexins inhibit the growth of fungi. They also secrete toxins to stop insect feeding to limit the spread by vectors

Question 40

How does inflammation work?

Answer 40

The body releases a molecule to increase the permeability of the blood vessels so they can leak fluids surrounding the damaged tissues to isolate any pathogens that may have entered. This also causes vasodilation so it increases blood flow to get more WBC to the area