What will happen to the apples after one week?

Question

Pathogens spread through either contact with living organisms, through the air, or contaminated objects, soil, or water. In this activity, you will see how pathogens spread in contaminated apples.

Procedure:

1. Label the plastic bags 1−4.

2. Put an apple into Bag 1 and seal it.

3. Rub a rotting apple over the entire surface of the remaining three fresh apples.

4. Put one of the apples into Bag 2 and seal it.

5. Drop an apple to the floor from a height of about two meters. Put the apple into Bag 3 and seal it.

6. Wipe rubbing alcohol over the entire surface of the last apple. Put the apple into Bag 4 and seal it.

7. Place all four bags in a dark place for one week.

8. At the end of the week, record your observations.

Observation after one week

Apple 1

Apple 2

Apple 3

Apple 4

Answer 1

Apple 1 should have minimal or no rotting because of its lack of exposure to pathogens. A pathogen is a microscopic organism that causes disease in another organism. A rotting apple contains pathogens that can spread to other apples and infect them. Without exposure to pathogens, Apple 1 should be in healthy condition after a week.

Apple 2 is likely to resemble the original rotting apple because it had direct exposure to the pathogens from the rot when the apple was rubbed over its surface.

Apple 3 should be in even worse condition than Apple 2. Observations are likely to include bruising and severe rotting. When dropped from a high height, an apple may split apart, making it even easier for pathogens to invade. Undamaged apple peel acts as a protectant for the fruit inside.

Apple 4 may have some rotting or damage but it will likely be observed that it is minimal compared to Apple 2 and Apple 3 because isopropyl alcohol kills pathogens and would have protected the apple from the infection, at least to some extent.