Module 2 Intro: Lesson 2 Intro

1. Module 2 Intro

1.7. Lesson 2 Intro

Module 2 Lesson 2

Module 2—Biosphere Equilibrium and the Impact of Humans

Lesson 2—Gas Exchange Equilibrium

Get Focused

What could possibly be happening to the air around you? In this video of the moose drinking water, you should be able to identify two activities that are happening which contribute to the equilibrium of oxygen and carbon dioxide (photosynthesis and cellular respiration). Unfortunately, studies of the Arctic seem to indicate that there is an imbalance in the exchange of oxygen and carbon dioxide. It is feared that climate change is a result of an imbalance in gas exchange and, if not counteracted, the biosphere could be in big trouble. How do scientists know that there are changes in Earth’s atmosphere? What do they know about past atmospheric conditions on Earth?

Scientists have conducted many studies focused on how the biosphere regulates itself. In 1985, construction began on Biosphere 2, a structure built with a closed artifical ecological system designed to study the complex web of interactions of life systems. Using Biosphere 2, scientists could alter the biosphere balance without affecting the real biosphere.

While the Biosphere 2 project was considered by many people in the scientific community to be unsuccessful, it did provide some valuable information. And it did show that the biosphere and its dynamic balance is something that humans cannot easily recreate. One key idea that scientists in Biosphere 2 studied was atmosphere composition, since humans need oxygen to keep alive and plants (autotrophs) need CO2 to survive. In 2007, the University of Arizona took over research at Biosphere 2.

In this lesson you will be exploring the following essential question:

How does the relationship between gas exchange in photosynthesis and cellular respiration influence the composition of the atmosphere?

Module 2: Lesson 2 Assignment

Your teacher-marked Module 2: Lesson 2 Assignment requires you to submit a response to the following:

TR 1. The Changing Atmosphere and Global Warming
Lesson 2 Lab: Biosphere in a Bottle

You can access your Module 2: Lesson 2 Assignment. You can print off the assignment or save the download to your computer. Your answers can be saved on this document to your course folder.

You must decide what to do with the questions that are not marked by the teacher.

Remember that these questions provide you with the practice and feedback that you need to successfully complete this course. You should respond to all the questions and place those answers in your course folder.