Diseases + Immune system

Question 1

4 pathogens that can cause diseases

Answer 1

• Bacteria
• Fungi
  -Virus
  -Protoctista

Question 2

How does Mycobacterium tuberculosis cause disease?

Answer 2

1) triggers the inflammatory response by infection phagocytes in the lungs
2) these phagocytes are sealed in a waxy coated vessel, so the bacteria remains dormant
3) if another factor weakens immune system, bacteria becomes active and destroys lung tissue

Question 3

How does HIV result in the symptoms of AIDS?

Answer 3

1) complementary proteins bind to the T-helper cells receptors
2)HIV particles replicate inside T-helper cells and kills/damage them
3) when there are few/no T-helper cells AIDS develops because the immune system cant operate
4) the individual may have secondary diseases or die if their body cannot fight off the pathogen

Question 4

Define INFECTIOUS disease

Answer 4

Disease caused by a pathogen that passes from infected individuals to uninfected individuals

Also known as communicable disease

Question 5

Define NON-INFECTIOUS disease

Answer 5

Long-term diseases that are not caused by pathogens.

Question 6

describe Bacteria

Answer 6

Some bacteria are non-pathogenic (they do not cause any disease or damage)
Pathogenic bacteria do not always infect the hosts of cells, they can remain within body cavities or spaces

Question 7

two diseases in ANIMALS from the pathogen BACTERIA

Answer 7

1) Tuberculosis (TB) - infects the lungs, causing a chronic cough and bloody mucus. Often associated with poor hygiene and sanitation

2) meningitis - crosses the barrier created by the meninges (the tissue that surrounds the brain and spinal cord) however N. meningitides crosses this barrier to cause acute inflammation

Question 8

what disease found in PLANTS are caused by BACTERIA

Answer 8

1) Ring rot - bacteria infect the vascular tissue and prevent the transport of water, causing the plant to wilt and die

Question 9

Describe how a virus works as a pathogen

Answer 9

• do not have a cellular structure
• This means they can’t respire, produce ATP, replicate genetic material or synthesise protein
• They infect host cells and hijack their machinery to replicate their genetic material and proteins

Question 10

what diseases are caused by VIRUSES in animals

Answer 10

1) Influenza - infect the cells that line the airways -> cause a high temperature, body aches and fatigue

2) HIV/AIDS -

Question 11

what disease is caused by VIRUSES in plants

Answer 11

Tobacco Mosaic Virus (TMV) - distinct yellowing of the leaves which produces a mosaic pattern