Ecosystems and populations of organisms within ecosystems function by the principle of balance and flux. Balance can be thought of as a state of equilibrium, or a state of equal changes between two sides. Flux can be thought of as a rate of flow or changes. Even small changes in an ecosystem's or population's balance and flux could lead to disaster.

Two lessons and their associated activities explore cellular respiration and population growth in yeasts. Yeast cells are readily obtained and behave predictably, so they are very appropriate to use in middle school classrooms. In the first lesson, students are introduced to yeast respiration through its role in the production of bread and alcoholic beverages. A discussion of the effects of alcohol on the human body is used both as an attention-getting device, and as a means to convey important information at an impressionable age. In the associated activity, students set up a simple way to indirectly observe and quantify the amount of respiration occurring in yeast-molasses cultures. Based on questions that arise from this activity, in the second lesson students work in small groups as they design and execute their own experiments to determine how environmental factors affect yeast population growth.

This class surveys developmental entrepreneurship via case examples of both successful and failed businesses and generally grapples with deploying and diffusing products and services through entrepreneurial action. By drawing on live and historical cases, especially from South Asia, Africa, Latin America as well as Eastern Europe, China, and other developing regions, we seek to cover the broad spectrum of challenges and opportunities facing developmental entrepreneurs. Finally, we explore a range of established and emerging business models as well as new business opportunities enabled by developmental technologies developed in MIT labs and beyond.

Dr. Joseph Bookstein argues that the real cause of global warming is not the burning of fossil fuels but rather the needs and wants of the global human population, now over 6.6 billion. He discusses methods, feasibility, and implementation strategies for voluntary population reduction. (52 minutes)

Basic subject in ecology: understanding the flow of energy and materials through ecosystems, and what regulates the distribution and abundance of organisms. Productivity and biogeochemical cycles in ecosystems; trophic dynamics; community structure and stability; competition and predation; evolution and natural selection; population growth; and physiological ecology. Emphasis on aquatic systems.

Students set up and run the experiments they designed in the lesson Population Growth in Yeasts, using simple yeast-molasses cultures in test tubes. Population growth is indicated by the amount of respiration occurring in the cultures, which in turn is indicated by the growth of carbon dioxide bubbles trapped within the culture tubes. Using this method, students can test for a variety of environmental influences, such as temperature, food supply, and pH.

In this activity, students will simulate the equal and unequal distribution of our renewable resources. Also, they will consider the impact of our increasing population upon these resources and how engineers develop technologies to create resources.

Here we see an image of the Baltimore Maryland area taken with the Landsat satellite. Dates ranging from 1986, 1990, 1996, 2000. For over 26 years, Landsat images have been used to help urban planners understand where growth is taking place and help geographers evaluate how different urban planning programs effect population growth and land use.

Here we see an image of the Washington,DC area taken with the Landsat satellite. The dates of the images are from 1986, 1990, 1996, 2000. For over 26 years, Landsat images have been used to help urban planners understand where growth is taking place and help geographers evaluate how different urban planning programs effect population growth and land use.

Here we see an image of the Washington,DC-Baltimore area taken with the Landsat satellite on March 27, 1998. For over 26 years, Landsat images have been used to help urban planners understand where growth is taking place and help geographers evaluate how different urban planning programs effect population growth and land use.

The MIT Biology Department core courses, 7.012, 7.013, and 7.014, all cover the same core material, which includes the fundamental principles of biochemistry, genetics, molecular biology, and cell biology. Biological function at the molecular level is particularly emphasized and covers the structure and regulation of genes, as well as, the structure and synthesis of proteins, how these molecules are integrated into cells, and how these cells are integrated into multicellular systems and organisms. In addition, each version of the subject has its own distinctive material. 7.014 focuses on the application of these fundamental principles, toward an understanding of microorganisms as geochemical agents responsible for the evolution and renewal of the biosphere and of their role in human health and disease.

This lesson is the second of two that explore cellular respiration and population growth in yeasts. In the first lesson, students set up a simple way to indirectly observe and quantify the amount of respiration occurring in yeast-molasses cultures. Based on questions that arose during the first lesson and its associated activity, in this lesson students work in small groups to design experiments that will determine how environmental factors affect yeast population growth.

This course presents the principles of evolution, ecology, and behavior for students beginning their study of biology and of the environment. It discusses major ideas and results in a manner accessible to all Yale College undergraduates. Recent advances have energized these fields with results that have implications well beyond their boundaries: ideas, mechanisms, and processes that should form part of the toolkit of all biologists and educated citizens.

Students will work in small groups to use the Internet to gather data on the population growth for each of the 100 counties in NC from 1992 to 1995. From this data students will find the percent of increase/decrease for the counties they have been assigned. As a follow-up, the students will enter their data into a computer spreadsheet and from that spreadsheet, produce graphs of the information.