Question

analysis

1. draw a diagram showing how the bubonic plague is spread. if you draw pictures, there must be descriptions. 4

Explanation:

The bubonic plague is spread by fleas (Xenopsylla cheopis) that infest rats (especially black rats, Rattus rattus). Here's a step - by - step breakdown for the diagram:

1. Reservoir Host (Rats): Rats are infected with the plague bacteria (Yersinia pestis). They live in areas with poor sanitation, like old - style cities with dirty streets and crowded housing.
2. Vector (Fleas): Fleas bite infected rats. The bacteria multiply in the flea's gut. When the rat dies (due to the infection), the flea looks for a new host.
3. Transmission to Humans: The infected flea then bites a human. The bacteria enter the human's body through the flea bite.
4. Human - to - Human (Rare, via Pneumonic Plague): In some cases, if a person develops pneumonic plague (an infection of the lungs), they can spread the bacteria through respiratory droplets when they cough or sneeze. But for bubonic plague, the main route is flea - rat - human.

To draw the diagram:

• Draw a rat and label it "Infected Rat (Reservoir Host)".
• Draw a flea on the rat and label it "Infected Flea (Vector)". Add an arrow from the rat to the flea with a note like "Flea bites infected rat, ingests Yersinia pestis".
• Draw a human and an arrow from the flea to the human with a note like "Infected flea bites human, transmits bacteria".
• Optionally, draw a cough - ing human and an arrow to another human with a note "Pneumonic plague transmission (rare for bubonic)".

Answer:

A diagram (or description of a diagram) showing the spread of bubonic plague can be constructed as follows:

1. Reservoir (Rats): Represent rats (e.g., black rats) as the reservoir of Yersinia pestis.
2. Vector (Fleas): Show fleas (e.g., Xenopsylla cheopis) feeding on infected rats, with bacteria multiplying in flea guts.
3. Transmission to Humans: Depict fleas biting humans, transferring bacteria (leading to bubonic plague, marked by swollen lymph nodes or “buboes”).
4. Optional: Pneumonic Spread: (Rare for bubonic) Show respiratory transmission between humans if pneumonic plague develops.

Labels and arrows should connect these elements, with descriptions explaining each step (e.g., “Flea bites infected rat → ingests bacteria; Flea bites human → transmits bacteria to human via bite”).