Disease Defences 6.3

Question 1

What is the essential idea?

Answer 1

The human body has structures and processes that resist the continuous threat of invasion by pathogens

Question 2

What are the primary defences against a disease?

Answer 2

mucus and skin

Question 3

How are cuts in the skin sealed?

Answer 3

by blood clotting

Question 4

From where are clotting factors released?

Answer 4

from platelets

Question 5

What is the cascade?

Answer 5

the rapid conversion of fibrinogen -> fibrin by thrombin

Question 6

What is non-specific immunity?

Answer 6

Ingestion of pathogens by phagocytic white blood cells

Question 7

What is specific immunity?

Answer 7

Production of antibodies by lymphocytes in response to particular pathogens

Question 8

What do antibiotics block?

Answer 8

processes that occur in prokaryotic cells but not in eukaryotic cells

Question 9

Why can’t viruses be treated with antibiotics?

Answer 9

because they don’t have a metabolism

Question 10

What did genes of bacteria evolve to?

Answer 10

resistant genes to antibiotics

Question 11

What is Chemotaxis?

Answer 11

movement in response to chemicals

Question 12

Chemotaxis attracts phagocytes as a response to:

Answer 12

• proteins produced by the pathogen
• phospholipids released by damaged cells

Question 13

What are the steps to attack a pathogen?

Answer 13

• phagocyte attaches the pathogen’s cell surface proteins and then engulfs it
• a phagosome forms (the vesicle that contains the pathogen)
• lysosomes deposit digestive enzymes into the phagosome
• the enzymes break down the pathogen and waste products are expelled through exocytosis