Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.

By the end of this section, you will be able to:List the characteristics of fungiDescribe the composition of the myceliumDescribe the mode of nutrition of fungiExplain sexual and asexual reproduction in fungi

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.

The need to identify sustainable forms of energy as an alternative to our dependence on depleting worldwide oil reserves is one of the grand challenges of our time. The energy from the sun converted into plant biomass is the most promising renewable resource available to humanity. This seminar will examine each of the critical steps along the pathway towards the conversion of plant biomass into ethanol. This course is one of many Advanced Undergraduate Seminars offered by the Biology Department at MIT. These seminars are tailored for students with an interest in using primary research literature to discuss and learn about current biological research in a highly interactive setting. Many instructors of the Advanced Undergraduate Seminars are postdoctoral scientists with a strong interest in teaching.

Students set up and run the experiments they designed in the Population Growth in Yeasts associated lesson, 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 test for a variety of environmental influences, such as temperature, food supply and pH.

This seminar is designed to be an experimental and hands-on approach to applied chemistry (as seen in cooking). Cooking may be the oldest and most widespread application of chemistry and recipes may be the oldest practical result of chemical research. We shall do some cooking experiments to illustrate some chemical principles, including extraction, denaturation, and phase changes.

Students design systems that use microbes to break down a water pollutant (in this case, sugar). They explore how temperature affects the rate of pollutant decomposition.

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.

In this activity, students act as environmental engineers involved with the clean up of a toxic spill. Using bioremediation as the process, students select which bacteria they will use to eat up the pollutant spilled. Students learn how engineers use bioremediation to make organism degrade harmful chemicals. Engineers must make sure bacteria have everything they need to live and degrade contaminants for bioremediation to happen. Students learn about the needs of living things by setting up an experiment with yeast. The scientific method is reinforced as students must design the experiment themselves making sure they include a control and complete parts of a formal lab report.

Students are presented with information that will allow them to recognize that yeasts are unicellular organisms that are useful to humans. In fact, their usefulness is derived from the contrast between the way yeast cells and human cells respire. Specifically, while animal cells derive energy from the combination of oxygen and glucose and produce water and carbon dioxide as by-products, yeasts respire without oxygen. Instead, yeasts break glucose down and produce alcohol and carbon dioxide as their by-products. The lesson is also intended to provoke questions from students about the effects of alcohol on the human body, to which the teacher can provide objective answers.

Students set up a simple way to indirectly observe and quantify the amount of respiration occurring in yeast-molasses cultures. Each student adds a small amount of baking yeast to a test tube filled with diluted molasses. A second, smaller test tube is then placed upside-down inside the solution. As the yeast cells respire, the carbon dioxide they produce is trapped inside the inverted test tube, producing a growing bubble of gas that is easily observed and measured. Students are presented with the procedure for designing an effective experiment; they learn to think critically about experimental results and indirect observations of experimental events.