Exam 25: Global Change

Which of the following statements is not correct?

Which of the following represents the most significant anthropogenic modification to the nitrogen cycle?

When biologically usable nitrogen is increased in terrestrial communities, net primary productivity usually ____________________.

Atmospheric scientists anticipate a 3.5°C temperature rise in the next century; if so, what impacts will such change bring?

The physical and biotic changes humans make to the land surface of Earth are collectively known as land ____________________.

Wetlands are one of the few habitats to have escaped human-caused destruction; the worldwide distribution of wetlands has remained relatively stable for the past 200 years.

The organisms responsible for most of the conversion of atmospheric molecular nitrogen (N₂)to the nitrate or ammonium that can be used by most other organisms are

All global changes presently observed on Earth are due to human activity.

Converting atmospheric nitrogen into chemical forms that can be used biologically is called fixation. Which of the following organisms can fix nitrogen?

The atmospheric concentration of carbon dioxide is presently approaching values equal to those believed to have existed 420,000 years ago.