Question

australia is a large island continent. cane toads first came to australia in 1935. they were brought into the country to control beetles that ate crops. however, the toads eat a wide variety of native organisms. the toads also produce a venom which can kill the organisms that prey on them. the australian government is now trying to remove all cane toads.
which evidence best supports the effort to remove all cane toads from australia?
a. cane toads disrupt food webs in the ecosystem.
b. humans actions can negatively affect ecosystems.
c. island ecosystems are more fragile than continental ecosystems.
d. native species may breed with cane toads and pass on their traits.

Explanation:

The text states that cane toads eat native organisms and their venom kills their predators. This disrupts the food web as it affects both the prey (native organisms eaten by toads) and the predators (killed by toad venom). A disrupted food web is a strong reason for removal. Option B is too general about human actions. Option C about island vs continental ecosystems is not supported by the given text. Option D about breeding is not mentioned in the provided information.

Answer:

A. Cane toads disrupt food webs in the ecosystem.