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Science of Food Safety: Microbes, Friend or Foe Science Object
Science Object
Science of Food Safety: Microbes, Friend or Foe
Grade Level: Elementary School, Middle School
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between FDA and NSTA, is the third of four Science Objects in the Science of Food Safety SciPack. It explores how bacteria live in close concert with humans. Bacteria are masters at exploiting a variety of niches in the human body and live in huge colonies in places such...  [view full summary]

Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between FDA and NSTA, is the third of four Science Objects in the Science of Food Safety SciPack. It explores how bacteria live in close concert with humans. Bacteria are masters at exploiting a variety of niches in the human body and live in huge colonies in places such as the skin, intestines and mouth. Most of these bacteria are harmless to the human body, and many are important in assisting its normal, healthy functioning. Disease in humans results when organisms such as bacteria interfere with the normal operation of the human body, most commonly foreign organisms entering the body. The human body has many mechanisms to protect itself against outside organisms that may interfere with its normal operation.

Bacteria that gain entrance to the body may form colonies in preferred organs or tissues, emitting harmful toxins as waste products. If the body's immune system cannot suppress a bacterial infection, an antibacterial drug may be effective—at least against the types of bacteria it was designed to combat. Viruses invade healthy cells and cause them to synthesize more viruses, usually killing those cells in the process.


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Science of Food Safety: Growth and Reproduction of Cells Science Object
Science Object
Science of Food Safety: Growth and Reproduction of Cells
Grade Level: Elementary School, Middle School
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between FDA and NSTA, second of four Science Objects in the Food Science Safety SciPack. It explores cell functions involving chemical reactions that are made possible by protein catalysts called enzymes. These reactions require a fairly narrow range of temperature and...  [view full summary]
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between FDA and NSTA, second of four Science Objects in the Food Science Safety SciPack. It explores cell functions involving chemical reactions that are made possible by protein catalysts called enzymes. These reactions require a fairly narrow range of temperature and pH. Low temperatures cause them to go too slowly, and high temperatures or acidity can change cell structures. Molecules from the environment may also attach to or pass through a cell's membrane and affect reaction rates. Cells such as bacteria require energy and nutrients from their environment for survival. When they grow to a certain size, bacteria can reproduce by creating a copy of their DNA and then splitting in two. Under optimal conditions, this doubling of bacteria and each of their generated offspring can proceed at a fast rate, expanding a bacterial colony rapidly in a short time. Many of the precautions taken to protect the health of humans focus on limiting the growth of bacterial colonies by creating environmental conditions not favorable for their functioning or reproduction. Variations in genetic information within a population of bacteria can permit some individuals to survive and reproduce more effectively than others in a given environment. Such hardier individuals usually represent only tiny fractions of a population, but their rapid reproduction can quickly give rise to large numbers of successful offspring. This process may give rise to bacterial strains able to survive under new conditions, such as strains with resistance to overused antibacterial drugs, or grant previously harmless bacteria the ability to cause disease.


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Science of Food Safety: Understanding the Cell's Importance Science Object
Science Object
Science of Food Safety: Understanding the Cell's Importance
Grade Level: Elementary School, Middle School
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between FDA and NSTA, is the first of four Science Objects in the Science of Food Safety SciPack. It explores self-replicating life forms, which are all composed of cells. Living cells contain similar types of complex molecules that support the basic activities of life....  [view full summary]

Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between FDA and NSTA, is the first of four Science Objects in the Science of Food Safety SciPack. It explores self-replicating life forms, which are all composed of cells. Living cells contain similar types of complex molecules that support the basic activities of life. These molecules interact in a soup, composed of about 2/3 water, surrounded by a membrane that controls what can enter and leave the cell. Cells have particular structures for cell functions, protection, and in some cases the ability to move. A single living cell represents the smallest individual unit of life. Single-celled organisms vary in the complexity of their structure and the amount of genetic material they contain, and populate all environments on Earth in astounding numbers and types. Those with less genetic material and simpler structures are more numerous. Bacteria are one type of single-celled organism that have an interdependent relationship with humans.


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Gravity and Orbits: Gravitational Force Science Object
Science Object
Gravity and Orbits: Gravitational Force
Grade Level: Elementary School, High School, Middle School
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between NASA and NSTA, is the second of three Science Objects in the Gravity and Orbits SciPack. It investigates the variables that influence gravitational forces acting on objects. Mass is a measure of the amount of matter that makes up an object (regardless of where...  [view full summary]
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between NASA and NSTA, is the second of three Science Objects in the Gravity and Orbits SciPack. It investigates the variables that influence gravitational forces acting on objects. Mass is a measure of the amount of matter that makes up an object (regardless of where that object is located) and weight is a measure of the gravitational force acting on an object. The strength of the gravitational force between masses is proportional to the product of the masses and inversely proportional to the square of the distance between them. Gravity will cause all objects at the same distance from Earth’s surface to fall toward Earth with the same acceleration regardless of their mass.
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Gravity and Orbits: Universal Gravitation Science Object
Science Object
Gravity and Orbits: Universal Gravitation
Grade Level: Elementary School, High School, Middle School
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between NASA and NSTA, is the first of three Science Objects in the Gravity and Orbits SciPack. It provides an understanding of gravitational forces associated with all objects that have mass. Every object exerts a gravitational force on every other object. The force is...  [view full summary]
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between NASA and NSTA, is the first of three Science Objects in the Gravity and Orbits SciPack. It provides an understanding of gravitational forces associated with all objects that have mass. Every object exerts a gravitational force on every other object. The force is hard to detect unless at least one of the objects has a lot of mass. Any two objects will exert an equal gravitational force (in opposite directions) on one another. Gravity is the force behind the falling rain and flowing rivers, and is responsible for pulling the matter that makes up planets and stars toward their centers to form spheres.
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Science of Food Safety: Food Safety and You Science Object
Science Object
Science of Food Safety: Food Safety and You
Grade Level: Elementary School, Middle School
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between FDA and NSTA, is the last of four Science Objects inthe Science of Food Safety SciPack. It explores the scientist involved with the development of germ theory and pasteurization, which brought about great changes in the safe handling of food and water, and improved...  [view full summary]

Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object, co-developed between FDA and NSTA, is the last of four Science Objects inthe Science of Food Safety SciPack. It explores the scientist involved with the development of germ theory and pasteurization, which brought about great changes in the safe handling of food and water, and improved sanitation measures that represent some of the greatest public health contributions to date. More recently, humans have instituted laws requiring the monitoring of air, soil, and water for microorganisms that pose a threat to human health. Such agricultural and food safety regulations represent social trade-offs that ensure the population's general welfare at the price of increased cost or lowered efficiency. In addition to these large-scale societal precautions, humans rely heavily on personal measures to limit the transmission of invasive organisms into their bodies. These measures include keeping hands and skin clean, avoiding contaminated foods and liquids, cleaning and separating food items properly during preparation, cooking food at high enough temperatures for proper lengths of time, and keeping the temperature of food sufficiently low at all times when it is not being prepared or consumed.


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Force and Motion: Newton's Third Law Science Object
Science Object
Force and Motion: Newton's Third Law
Grade Level: Elementary School, High School, Middle School
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the last of four Science Objects in the Force and Motion SciPack. It provides a conceptual and real-world understanding of Newton’s Third Law of Motion, addressing common misconceptions associated with this law. Whenever one object exerts a force on another, an equal amount of force...  [view full summary]
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the last of four Science Objects in the Force and Motion SciPack. It provides a conceptual and real-world understanding of Newton’s Third Law of Motion, addressing common misconceptions associated with this law. Whenever one object exerts a force on another, an equal amount of force is exerted back on it. These equal and opposite forces are exerted simultaneously on the objects involved.
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Force and Motion: Newton's Second Law Science Object
Science Object
Force and Motion: Newton's Second Law
Grade Level: Elementary School, High School, Middle School
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of four Science Objects in the Force and Motion SciPack. It provides a conceptual and real-world understanding of Newton’s Second Law of Motion. An object’s change in motion is proportional to the net force applied to the object and inversely proportional to the mass of...  [view full summary]
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of four Science Objects in the Force and Motion SciPack. It provides a conceptual and real-world understanding of Newton’s Second Law of Motion. An object’s change in motion is proportional to the net force applied to the object and inversely proportional to the mass of the object (being the measure of its inertia). The magnitude of the change in motion can be calculated using the relationship F = ma, which is independent of the nature of the force acting on the object.
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Force and Motion: Newton's First Law Science Object
Science Object
Force and Motion: Newton's First Law
Grade Level: Elementary School, High School, Middle School
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the second of four Science Objects in the Force and Motion SciPack. It provides a conceptual and real-world understanding of Newton’s First Law of Motion. All objects will maintain a constant speed and direction of motion unless an unbalanced outside force acts on it. When an unbalanced...  [view full summary]
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the second of four Science Objects in the Force and Motion SciPack. It provides a conceptual and real-world understanding of Newton’s First Law of Motion. All objects will maintain a constant speed and direction of motion unless an unbalanced outside force acts on it. When an unbalanced force acts on an object, its speed or direction (or both) will change. The tendency of objects to maintain a constant speed and direction of motion (velocity) in the absence of an unbalanced force is known as intertia. Even in the most familiar, every day situations, frictional forces can complicate the analysis of motion, although the basic principles still apply.
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Flow of Matter and Energy in Ecosystems: Nothing Matters Without Energy Science Object
Science Object
Flow of Matter and Energy in Ecosystems: Nothing Matters Without Energy
Grade Level: Elementary School, High School, Middle School
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of three Science Objects in the Flow of Matter and Energy in Ecosystems SciPack. It explores how energy flows through an ecosystem in one direction, from photosynthetic organisms to herbivores to omnivores and carnivores and decomposers. As the energy flows, less and...  [view full summary]
Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the third of three Science Objects in the Flow of Matter and Energy in Ecosystems SciPack. It explores how energy flows through an ecosystem in one direction, from photosynthetic organisms to herbivores to omnivores and carnivores and decomposers. As the energy flows, less and less energy isavailable to support life.

Plants capture the sun's energy and use it to synthesize complex, energy-rich molecules (chiefly sugars) from molecules of carbon dioxide and water. Because plants and other photosynthetic organisms use energy from the sun and inorganic molecules from the environment to produce organic molecules needed for life, they are called producers. The organisms that consume the producers (called consumers) derive energy and materials from breaking down the producers’ molecules, use them to synthesize their own structures and then may be consumed by other organisms. Decomposers (organisms that break down dead producers and consumers and organic waste) obtain the energy they need to live from chemical bonds of the dead and waste-matter. The energy is transferred both to the decomposer (for growth and development) and to the ecosystem (as heat energy). Food webs and energy pyramids are models or representations that can be used to track the flow of energy in the ecosystem. Food webs detail the flow of energy through the populations in the ecosystems whereas the pyramid model quantifies the flow of energy through various levels in an ecosystem. Unlike matter, as energy flows through an ecosystem in one direction, from photosynthetic organisms to herbivores to omnivores and carnivores and decomposers, less and less energy becomes available to support life. This loss of useable energy occurs because each energy transfer results in the dissipation of some energy into the environment as heat. Continual input of energy from sunlight is necessary to keep ecosystems organized and functioning.

Learning Outcomes:
  • Explain how a food web describes the flow of energy within an ecosystem
  • Explain the role that the amount of sunlight available to an ecosystem plays on defining the size and types of populations within an ecosystem
  • Use the characteristics of energy transfer (from one population to another) to explain the structure of an energy pyramid for organisms living in a community
  • Explain why, if energy is conserved in the interaction of consumers and producers, there is less energy at the consumer level compared to the producer level in an energy pyramid
  • Explain why a vegetarian diet for humans requires less energy to produce the food needed than a diet that includes meat and fish does
  • Compare the flow of matter with the flow of energy among organisms and between organisms and their environment in an ecosystem

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