Students figure out that they can trace all food back to plants, including processed and synthetic food. They obtain and communicate information to explain how matter gets from living things that have died back into the system through processes done by decomposers. Students finally explain that the pieces of their food are constantly recycled between living and nonliving parts of a system.

This unit on matter cycling and photosynthesis begins with students reflecting on what they ate for breakfast. Students are prompted to consider where their food comes from and consider which breakfast items might be from plants. Then students taste a common breakfast food, maple syrup, and see that according to the label, it is 100% from a tree.

Based on the preceding unit, students argue that they know what happens to the sugar in syrup when they consume it. It is absorbed into the circulatory system and transported to cells in their body to be used for fuel. Students explore what else is in food and discover that food from plants, like bananas, peanut butter, beans, avocado, and almonds, not only have sugars but proteins and fats as well. This discovery leads them to wonder how plants are getting these food molecules and where a plant’s food comes from.

Students learn a simple technique for quantifying the amount of photosynthesis that occurs in a given period of time, using a common water plant (Elodea). They can use this technique to compare the amounts of photosynthesis that occur under conditions of low and high light levels. Before they begin the experiment, however, students must come up with a well-worded hypothesis to be tested. After running the experiment, students pool their data to get a large sample size, determine the measures of central tendency of the class data, and then graph and interpret the results.

The purpose of this resource is to observe budburst on selected trees at a Land Cover or Phenology Site. All students will learn about hummingbird natural history and ecology. Students will learn how to identify and age male and female Ruby-throated Hummingbirds and to observe migration and feeding behavior. Students will learn how to make connections among hummingbird behavior and weather, climate, food availability, seasonality, photoperiod (day length), and other environmental factors.

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.

Students are introduced to the concept of energy cycles by learning about the carbon cycle. They will learn how carbon atoms travel through the geological (ancient) carbon cycle and the biological/physical carbon cycle. Students will consider how human activities have disturbed the carbon cycle by emitting carbon dioxide into the atmosphere. They will discuss how engineers and scientists are working to reduce carbon dioxide emissions. Lastly, students will consider how they can help the world through simple energy conservation measures.

In this experiment, students observe a natural process that removes carbon dioxide (CO2) from Earth's atmosphere. This process is a part of the carbon cycle and results in temperature suitable for life. Students learn that the carbon cycle is a fundamental Earth process. Throughout Earth's history, the balance of carbon has kept the atmosphere's carbon dioxide (CO2) and Earth's temperature within relatively narrow ranges.

Through a teacher-led discussion, students realize that the food energy plants obtain comes from sunlight via the plant process of photosynthesis. They learn what photosynthesis is, at an age-appropriate level of detail and vocabulary, and then begin to question how we know that photosynthesis occurs, if we can't see it happening. Elodea is a common water plant that students can use to directly observe evidence of photosynthesis. When Elodea is placed in a glass beaker near a good light source, bubbles of oxygen will be released as products of photosynthesis. By counting the number of bubbles that rise to the surface in a five-minute period, students can compare the photosynthetic activity of Elodea in the presence of high and low light levels.

Students learn how rooftop gardens help the environment and the lives of people, especially in urban areas. They gain an understanding of how plants reduce the urban heat island effect, improve air quality, provide agriculture space, reduce energy consumption and increase the aesthetic quality of cities. This draws upon the science of heat transfer (conduction, convection, radiation, materials, color) and ecology (plants, shade, carbon dioxide, photosynthesis), and the engineering requirements for rooftop gardens. In the associated activity, students apply their scientific knowledge to model and measure the effects of green roofs.

This set of five activities focuses on how climate change can affect agriculture, including crop production and ranching. The activities in this guide are appropriate for both formal and informal settings and all student handouts, instructor guides, and supporting files are included. The curriculum is designed for five days of activities that build on one another, but can also be used individually.

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

The purpose of this resource is to observe plant green-down and report greendown data to help validate estimates of the end of the plant growing season. Students monitor the change in color of selected leaves of trees, shrubs or grasses.

The purpose of this resource is to observe plant green-up and report data that will be used by scientists to validate satellite estimates of the beginning of the plant growing season. Students monitor budburst and growth of leaves of selected trees, shrubs, or grasses. Species chosen should be native, deciduous, and dominant in your area.

Students are presented with a guide to rain garden construction in an activity that culminates the unit and pulls together what they have learned and prepared in materials during the three previous associated activities. They learn about the four vertical zones that make up a typical rain garden with the purpose to cultivate natural infiltration of stormwater. Student groups create personal rain gardens planted with native species that can be installed on the school campus, within the surrounding community, or at students' homes to provide a green infrastructure and low-impact development technology solution for areas with poor drainage that often flood during storm events.

Through multi-trial experiments, students are able to see and measure something that is otherwise invisible to them seeing plants breathe. Student groups are given two small plants of native species and materials to enclose them after watering with colored water. After being enclosed for 5, 10 and 15 minutes, teams collect and measure the condensed water from the plants' "breathing," and then calculate the rates at which the plants breathe. A plant's breath is known as transpiration, which is the flow of water from the ground where it is taken up by roots (plant uptake) and then lost through the leaves. Students plot volume/time data for three different native plant species, determine and compare their transpiration rates to see which had the highest reaction rate and consider how a plant's unique characteristics (leaf surface area, transpiration rate) might figure into engineers' designs for neighborhood stormwater management plans.

This NetLogo model of leaf photosynthesis shows the macroscopic outcome of the reaction.

Through an overview of the components of the hydrologic cycle and the important roles they play in the design of engineered systems, students' awareness of the world's limited fresh water resources is heightened. The hydrologic cycle affects everyone and is the single most critical component to life on Earth. Students examine in detail the water cycle components and phase transitions, and then learn how water moves through the human-made urban environment. This urban "stormwater" water cycle is influenced by the pervasive existence of impervious surfaces that limit the amount of infiltration, resulting in high levels of stormwater runoff, limited groundwater replenishment and reduced groundwater flow. Students show their understanding of the process by writing a description of the path of a water droplet through the urban water cycle, from the droplet's point of view. The lesson lays the groundwork for rest of the unit, so students can begin to think about what they might do to modify the urban "stormwater" water cycle so that it functions more like the natural water cycle. A PowerPoint® presentation and handout are provided.

Students explore the phenomena of how a tree gets its mass. They are encouraged to think back to what they know about photosynthesis and explain what they know and what they wonder about the phenomena of a seed transforming into a large tree and having mass. Specifically, carbon is taken in from the atmosphere in the form of CO2 and transformed into glucose to provide energy and ultimately building material (cellulose). In this storyline, carbon sequestration refers to the removal of carbon (in the form of carbon dioxide) from the atmosphere through the process of photosynthesis. Carbon storage refers to the amount of carbon bound up in woody material above and below ground.  Carbon sequestration occurs in trees, other plants, the ocean, and soil. Not all plants sequester the same amount of carbon, for example, there’s a difference in the amount of carbon sequestered between young and old trees, and between different species of trees. This has implications for working forests and old growth forests. Using information from this storyline, students will draw conclusions about the value of managing forests to benefit human needs and natural needs.  

Los estudiantes exploran el fenómeno de cómo un árbol obtiene su masa. Se les anima a pensar en lo que saben sobre la fotosíntesis y explicar lo que saben y lo que se preguntan sobre el fenómeno de una semilla que se transforma en un árbol grande y tiene masa. Específicamente, el carbono se absorbe de la atmósfera en forma de CO2 y se transforma en glucosa para proporcionar energía y, en última instancia, material de construcción (celulosa). En este caso, la captura de carbono se refiere a la eliminación de carbono (en la forma de dióxido de carbono) de la atmósfera a través del proceso de fotosíntesis. El almacenamiento de carbono se refiere a la cantidad de carbono unido al material leñoso por encima y por debajo del suelo.  

This lesson covers the process of photosynthesis and the related plant cell functions of transpiration and cellular respiration. Students will learn how engineers can use the natural process of photosynthesis as an exemplary model of a complex yet efficient process for converting solar energy to chemical energy or distributing water throughout a system.