Question 15

[quadalpha]

Why must whether the pheromone is the only thing attracting flies be assumed? It only needs to be known whether it is a factor. The existence of water, for example, is likely also responsible for attracting flies which lay their eggs on water.

[jellywing_2058]

You are correct that water is necessary. However, according to the passage, female mosquitoes always lay their eggs on water; and that is excluded from the assumptions.

[quadalpha]

[dnpgr16513]

hi,

"The female mosquitoes lay their eggs on water. As the eggs mature they produce a chemical signal which attracts other egg-laying females to the site."

Although the females are initially attracted by the "egg-laying pheromones", after the eggs start mature they ALSO produce a chemical signal which attracts OTHER egg-laying females to the site. Wouldn't the maturing egg's releasing chemical also attract the females?

thanks!

[jeanne7524]

"Although the females are initially attracted by the "egg-laying pheromones", after the eggs start mature they ALSO produce a chemical signal which attracts OTHER egg-laying females to the site. Wouldn't the maturing egg's releasing chemical also attract the females? "

HI there!

The pheromones are the chemical signals produced by the eggs that are maturing. They are the same as the "maturing egg's releasing chemical" that you were referring in your question. So, in this case, there are no other factors mentioned in the passage.

Hope this gives light to your question.