CK-12’s Life Science delivers a full course of study in the life sciences for the middle school student, relating an understanding of the history, disciplines, tools, and modern techniques of science to the exploration of cell biology, molecular biology, genetics, evolution, prokaryotes, protists,fungi, plants, animals, invertebrates, vertebrates, human biology, and ecology. This digital textbook was reviewed for its alignment with California content standards.

In this lesson, students learn about the basics of cellular respiration. They also learn about the application of cellular respiration to engineering and bioremediation. And, students are introduced to the process of bioremediation and several examples of how bioremediation is used during the cleanup of environmental contaminants.

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.

Students become “experts” and make creative presentations about the different ecological roles of producers, consumers, and decomposers at local and global scales.

You are part of the NASA design crew and your task is to design a suit to keep the human body safe from the hazards of deep space. Are you up to the challenge? This is an ADA compliant document.

Living and working in space presents many challenges for humans. Use this ADA Compliant student guide to explore what many of those challenges are as well as possible solutions.

While living in space can seem like nothing but exciting, astronauts encounter many physical, biological, and psychological hazards. Use this guide to explore more about living and working in space.

In this easy-to-do activity you will simulate the fluid shift felt by astronauts upon entering space.

Have you ever dreamed of becoming an astronaut? Use this slide show presentation as an introduction to the many challenges of living and working in space.

Living and working in space presents many challenges for humans. Use this student guide to explore what many of those challenges are as well as possible solutions.

Phenomena: DDT was a commonly-used pesticide for insect control in the United States until it was cancelled in 1972 by the United State Environmental Protection Agency (EPA).  DDT was initially used by the military in WWII to control malaria, typhus, body lice, and bubonic plague. Populations of fish eating birds, fish, plant life in certain ecosystems were affected by the use of this chemical and other similar ones.Storyline: Students at a school nearby the Delaware Bay noticed a change in osprey population.  The students wanted to figure out why this was happening. The students decided as a class to research, collect data, and explain why the environmental changes were occurring.PE Alignment: MS-LS2-1 Analyze and interpret data to provide evidence for the effects of resources availability on organisms and populations of organisms in an ecosystemMS-LS2-4 Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.  MS-LS1-7 Develop a model to describe how food is rearranged through chemical reactions forming new molecules that support growth and/or release energy as this matter moves through an organism

Food waste is a major contributor to greenhouse gas. Wasted food and the resources to produce that food are responsible for approximately 8% of global greenhouse gas emissions. In this storyline, students learn about the resources required to produce food through following the carbon cycle and discover how food waste contributes to climate change. They will also learn the farm to table transport chain as well as how to conduct a food waste audit. Finally, the students will research solutions to the problem of food waste that can be applicable to their own lives, their school, and their community. 

El desperdicio de comida es un contribuyente mayor a los gases de efecto invernadero. La comida desperdiciada y los recursos usados en su producción son responsables por aproximadamente 8% de las emisiones globales de gases de efecto invernadero. En este caso, los estudiantes aprenderán sobre los recursos requeridos para producir comida siguiendo el ciclo del carbón y descubrirán cómo el desperdicio de comida contribuye al cambio climático. También aprenderán sobre la cadena de transporte de la granja a la mesa y cómo conducir una auditoría de desperdicio de comida. Finalmente, investigarán soluciones al problema de desperdicio de comida que pueden aplicar a sus propias vidas, su escuela y su comunidad.

Take a trip to the red planet to learn about the science of launching and landing a rover on another planet as well as the science that will be done once it is on the ground.

Preventing loss of bone density in microgravity will continue to be a challenge for astronauts in the future as they spend longer durations in space. Try out this activity to learn more.

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.