Biology Disease

Question 1

What is a virus

Answer 1

are pathogens and are about one-hundredth the size of bacteria

• do not need nutrients
• do not produce wastes or exchange gases with the environment

Question 2

What is a bacterium

Answer 2

are microscopic, unicellular organisms

Question 3

Immune system – first line of defence

Answer 3

• mucus
• saliva
• stomach acid
• skin
• urine flow
• tears

Question 4

Immune system – second line of defence

Answer 4

• phagocyte – eat and destroy pathogens
  
  • neutrophils
  • macrophages
• inflammation
• fever
  
  • increases temp above pathogens optimum
  • increase in temp increases activity of phagocytes

Question 5

Immune system – third line of defence

Answer 5

Kills pathogens that have entered the body but is adaptive meaning it is better able to destroy pathogens from previous infections.

• lymphocytes
  
  • which produces antibodies
• memory lymphocytes
  
  • stored after you encounter a particular pathogen so
    body can adapt to be equipped to fight the pathogen

Question 6

Why is taking antibiotics for a virus a waste of time?

Answer 6

Because they do not work against viruses due to the fact that viruses are constantly changing

Question 7

How do vaccines work?

Answer 7

they work by taking a small amount of the toxin produced by a bacterium and making it inactive