Question

the spread of pathogens
how do we get sick?
why?
communicable diseases are spread between individuals by different methods, but they are all caused by pathogens, which are commonly called \germs.\ knowledge of pathogens and the ways in which they can be spread helps humans understand and prevent disease outbreaks.
model 1 - the 1854 london cholera outbreak
(image of a map with water pumps and black boxes representing cholera deaths)

1. model 1 is a map of an area in london where a large number of cases of cholera occurred in 1854.

a. how many water pumps are shown on the map?
b. what do the black boxes represent on the map?
c. what do the relative sizes of the boxes represent?

Explanation:

Part a

Step1: Identify water pumps

Look at the map and count the labeled pumps: Pump 1, Pump 2, Pump 3, Pump 4.
<Visual Check: Locate each pump icon with labels>

Step2: Count the pumps

There are 4 pumps (Pump 1, Pump 2, Pump 3, Pump 4).

The map has a legend stating "Relative number of deaths due to cholera" for the black boxes. So they represent the relative number of cholera - related deaths.

Since the black boxes are labeled as representing the relative number of deaths due to cholera, the relative sizes of the boxes should represent the relative number of deaths (i.e., a larger box means more deaths, a smaller box means fewer deaths) in different areas.

Answer:

4

Part b