Farmer Fran sprays her sugarcane field with a highly effective pesticide called 'Bayou Bug Blast'. For five years the pesticide
works without a hitch, effectively killing almost all of the bayou weevils trying to eat Farmer Fran's crop. However, during the 6th year, some of the crop takes a hit. During the 7th year, she loses half of her crop, and during the 8th year, she loses almost the entire cane field to bayou weevils, despite using twice the usual dose of Bayou Bug Blast. What happened? A)
The sugar cane became used to the pesticide, rendering it ineffective.
B)
Bayou weevils over-populated, because Bayou Bug Blast killed all of the predatory insects.
C)
A small population of weevils survived on other food sources and returned to the sugar cane field to feed.
D)
The weaker weevils were killed, and Farmer Fran accidentally caused only pesticide-resistant beetles to survive.
<span>The situation is one similar to the development of antibiotic resistance. The initial five years of spraying wiped out most of the pests; however, the killing also helped the pesticide-resistant pests to survive and thrive since they had less competition. Over the period of five years, the pesticide resistance became more and more common among the beetles and in the eighth year, almost all of the beetles were resistant to the pesticide. Thus, the answer is D.</span>
Mutations are only passed on to offspring when they occur in germ cell DNA, which are the cells that create sperm or ova. The other kind of cells, somatic cells, are the rest of the cells in the body, and mutations that occur in these cells do not get passed on to offspring.
