Chapter 1. Life Cycle of a Frog

Which statement about the frog life cycle is true?

Which aspect of an adult frog’s biology would be most vulnerable to environmental changes brought on by an extended dry spell?

The Northern Casque-headed frog lives in hot desert regions of western Mexico. This frog burrows underground during the day, is active at night, and breeds only during the rainy season. Which statement provides a reason to explain this frog’s breeding behavior?

Four chemical compounds at various concentrations were tested for their effects on a single frog species. None of these compounds had any effect on the health or lifespan of an adult frog, but each had a specific effect on an earlier stage of development leading to the adult state as described in the table. Rate each compound as having a severe or mild/null effect on the ability of a population of frogs to maintain their population levels in the presence of the compound at the levels tested.