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Flow of Matter and Energy in Ecosystems: Carbon, Carbon Everywhere Science Object
Science Object
Flow of Matter and Energy in Ecosystems: Carbon, Carbon Everywhere
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 three Science Objects in the Flow of Matter and Energy in Ecosystems SciPack. It explores how the cycling of carbon and other nutrients from non-living to living components and back is one of the most important of ecosystem functions and is representative of the cycling...  [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 three Science Objects in the Flow of Matter and Energy in Ecosystems SciPack. It explores how the cycling of carbon and other nutrients from non-living to living components and back is one of the most important of ecosystem functions and is representative of the cycling of other elements.

All matter that comprises organic molecules, including hydrogen, oxygen, nitrogen, phosphorous and others are transferred cyclically among living organisms and their non-living environment. The cycling of elements from non-living to living components and back is one of the most important ecosystem characteristics. For example, carbon, an essential element in organic molecules, is conserved as it is transferred from inorganic carbon in an ecosystem to organic molecules in living organisms of the ecosystem and back as inorganic carbon to the environment. The carbon cycle, in the following description, serves as an example of one of the essential biogeochemical cycles.

Learning Outcomes:
  • Trace the path of a carbon atom from the atmosphere through a biomass pyramid and ultimately back to the atmosphere
  • Describe how photosynthesis and consumer respiration affect the flow of carbon through an ecosystem
  • Predict the biological effects of increasing levels of atmospheric carbon due to the massive combustion of fossil fuels
  • Identify the process that emits carbon to the atmosphere from producers, consumers and decomposers

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Heredity and Variation: Genes in Action Science Object
Science Object
Heredity and Variation: Genes in Action
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 three Science Objects in the Heredity and Variation SciPack. It explores sexual reproduction and the process of meiosis.

We now know that structures and functions at the molecular and cellular levels provide the mechanism for reproduction and the continuity...  [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 three Science Objects in the Heredity and Variation SciPack. It explores sexual reproduction and the process of meiosis.

We now know that structures and functions at the molecular and cellular levels provide the mechanism for reproduction and the continuity of species. Instructions for development are passed from parents to offspring in thousands of discrete genes, each of which is a segment of a molecule of DNA. An organism’s particular genetic information, coded in its DNA (genotype), contains genes that provide the information necessary to assemble proteins. Offspring of asexual organisms inherit all of the parent's genes. In organisms that reproduce sexually, specialized female and male sex cells (gametes) are formed during a process of cell division called meiosis. Each of these sex cells contains a random half of the parent's genetic information.

When a particular male gamete fuses with a particular female gamete during fertilization, they form a cell with one complete set of paired chromosomes, a combination of one half-set from each parent. This random combining of gametes and their chromosomes during fertilization results in millions of different possible combinations of genes, which causes the offspring genotypes to vary from their parents’. Some of the new gene combinations make little difference in the ability of the offspring to reproduce or survive, some can produce organisms with capabilities that enhance their ability to survive and reproduce, and some can be deleterious, resulting in an inability to survive and/or reproduce. Learning Outcomes:
  • Distinguish among the following structures by describing their relationship to one another: DNA, chromosomes, genes, and alleles.
  • Describe the role genes play in the production of proteins and defining the phenotype of an organism.
  • Compare and contrast the DNA in cells produced during asexual reproduction versus the DNA in gametes produced during meiosis.
  • Indentify and describe those steps within the process of meiosis that explain the random distribution of genotypes among offspring resulting from sexual reproduction.
  • Explain how the recombination of the allele pairs for individual genes during sexual reproduction results in phenotypic variation among offspring.

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Interdependence of Life: Population Balance in Biomes Science Object
Science Object
Interdependence of Life: Population Balance in Biomes
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 Interdependence of Life SciPack. It explores population balance in biomes.

Interdependent and fluctuating interactions among living organisms and populations and the abiotic components of their environment cause cyclical...  [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 Interdependence of Life SciPack. It explores population balance in biomes.

Interdependent and fluctuating interactions among living organisms and populations and the abiotic components of their environment cause cyclical changes in the overall ecosystem resource equilibrium.

Interactions among living organisms within a population and among organisms of different populations take place on an ever-changing environmental stage. The nonliving environment—including land and water, solar radiation, rainfall, mineral concentrations, temperature and topography—shapes Earth’s ecosystems. Because each species can tolerate a limited range of physical conditions, the diversity of physical conditions creates a wide variety of ecosystems. In all these environments organisms use vital, yet limited, resources; each seeking its share in specific ways that are limited by biotic and abiotic factors.

Learning Outcomes:
  • Explain why there are such diverse ecosystems on Earth.
  • Given a description of changes in abiotic factors defining an ecosystem (i.e. temperature, precipitation, soil composition, atmospheric composition, amount of available solar energy) and the tolerance of a few species to these factors, identify graphs that accurately predict their effects on size and growth rate of these species.
  • Identify and explain graphs that accurately represent examples of dynamic equilibrium.
  • Explain how the population sizes of predators and their prey maintain a balance over many generations.

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Flow of Matter and Energy in Ecosystems: Does Matter Matter? Science Object
Science Object
Flow of Matter and Energy in Ecosystems: Does Matter Matter?
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 first of three Science Objects in the Flow of Matter and Energy in Ecosystems SciPack. It explores the structure of the biomass in an ecosystem and overall cycling of matter. However complex the workings of living organisms, they share with all other systems the same physical...  [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 first of three Science Objects in the Flow of Matter and Energy in Ecosystems SciPack. It explores the structure of the biomass in an ecosystem and overall cycling of matter. However complex the workings of living organisms, they share with all other systems the same physical principles that describe the conservation and transformation of matter.

Ecosystems are a community of interdependent organisms and the chemical and physical factors making up the environment with which they interact. For every ecosystem on Earth there is a particular biomass (matter) distribution among organisms in its populations. While the specific biomass distribution in any given ecosystem is unique because of resource availability, there is a common overall biomass distribution pattern in all ecosystems. Greater biomass exists in populations that obtain matter from the physical environment than in populations that obtain matter from other living organisms. As matter flows through different levels of organization in living systems—cells, organs, organisms, communities—and between living systems and the physical environment, chemical elements are recombined in different ways. Matter is conserved through each change.

Learning Outcomes:
  • Define an ecosystem and understand how it comprises an interdependent community of organisms along with their interactions with the chemical and physical components of the environment
  • Categorize organisms in a community based on their sources of matter/biomass and nutrients as one of the following: producers, herbivores (primary consumers), carnivores (secondary consumers; tertiary or top-consumers),
  • omnivores, and decomposers
  • Predict the relative biomass for different levels in a biomass pyramid for a typical ecosystem
  • Explain how matter is conserved in the interactions between consumers and producers, but that in a biomass pyramid there is less biomass at the consumer level compared to the producer level

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Nature of Light: So, What is Light? Science Object
Science Object
Nature of Light: So, What is Light?
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 is the final of four Science Objects in the Nature of Light SciPack. It provides an understanding of how sometimes the nature and behavior of electromagnetic radiation such as light can be best described using a wave model, but at other times it can be best described by using a particle...  [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 final of four Science Objects in the Nature of Light SciPack. It provides an understanding of how sometimes the nature and behavior of electromagnetic radiation such as light can be best described using a wave model, but at other times it can be best described by using a particle model. Particles of light called photons contain discrete amounts of energy. The energy that a photon carries is directly proportional to its frequency. The energy of a photon is inversely proportional to the wavelength of the electromagnetic radiation. Each kind of atom or molecule can only gain or lose energy only in discrete amounts so they can absorb and emit light only at frequencies and wavelengths corresponding to these amounts. These combinations of wavelengths or spectra can be used to identify the substance.
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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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Interdependence of Life: Agents of Change in Ecosystems Science Object
Science Object
Interdependence of Life: Agents of Change in Ecosystems
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 fourth of four Science Objects in the Interdependence of Life SciPack. It explores agents of change in ecosystems.

Various influences (including human impact, natural disasters, climate change, and the appearance of new species) can force an ecosystem into...  [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 fourth of four Science Objects in the Interdependence of Life SciPack. It explores agents of change in ecosystems.

Various influences (including human impact, natural disasters, climate change, and the appearance of new species) can force an ecosystem into a state of different equilibrium. Depending on both the severity of the disturbance and the diversity of populations, feedback mechanisms may be sufficient to restore a state of equilibrium similar to the original ecosystem. However, if the disruptive influences are so severe (in duration and/or degree) they can push an ecosystem beyond its capacity to maintain equilibrium, irreversibly altering the system. In this case, a new point of dynamic equilibrium is eventually established, thus defining a new ecosystem.

Learning Outcomes:
  • Describe how populations might reach a new state of equilibrium following significant changes to the conditions (abiotic and biotic factors) defining their ecosystem.
  • Sequence and provide the rationale for a series of ecological processes that could logically occur following a large-scale disruption.
  • Given a description of factors that influence and affect population sizes in an ecosystem, identify those factors that could most likely contribute to an ecosystem’s long-term inability to return to dynamic equilibrium.
  • Explain how human activity (mining, dam construction, housing development) could affect the equilibrium of an ecosystem.

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Heredity and Variation: Inheritance Science Object
Science Object
Heredity and Variation: Inheritance
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 first of three Science Objects in the Heredity and Variation SciPack. It explores the historical perspective and experiments of Mendel. Sexual reproduction results in the continuity of species accompanied with a great deal of variation in physical traits. One familiar...  [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 first of three Science Objects in the Heredity and Variation SciPack. It explores the historical perspective and experiments of Mendel.

Sexual reproduction results in the continuity of species accompanied with a great deal of variation in physical traits. One familiar observation is that offspring are very much like their parents but still show some variation— differing somewhat from their parents and from one another. People have long been curious about heredity, using even the most primitive understanding of inheritance to cultivate desirable traits in domesticated species. In the 1800s, Gregor Mendel took his observations of heredity and variation to new heights through carefully designed and executed breeding experiments that generated repeatable inheritance patterns. Mendel developed a model for explaining the patterns he observed, describing discrete units or “particles,” which both segregate and assort independently of one another during inheritance. This model offered a foundational explanation for how variation is generated through sexual reproduction. Although Mendel’s model over-simplified how traits are inherited and expressed, it set the stage for the discoveries of chromosomes and genes from which contemporary genetics grew.

Learning Outcomes:
  • Explain how domestication of plants and animals produced an early understanding of inheritance.
  • Use Mendel’s model to explain patterns of inheritance represented in graphic form (for example, data tables, histograms, etc.).
  • Identify the conditions required for an inheritance pattern to be explained correctly by Mendel’s model.
  • Use data representing patterns of inheritance to support the idea that some observable traits are defined by discrete units of inheritance that segregate and assort independently of one another during inheritance.

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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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Cell Division and Differentiation: Variation and Specialization of Cells Science Object
Science Object
Cell Division and Differentiation: Variation and Specialization of Cells
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 three Science Objects in the Cell Division and Differentiation SciPack. It explores the processes that take place within cells that allow for selective gene expression, which leads to the specialization and variation of cells in organisms. Cell functions are turned...  [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 three Science Objects in the Cell Division and Differentiation SciPack. It explores the processes that take place within cells that allow for selective gene expression, which leads to the specialization and variation of cells in organisms.

Cell functions are turned on and off by regulatory genes, through changes in the activity of the functions performed by proteins. Although cells in a multi–celled organism begin alike, having essentially identical genetic instructions, selective expression of individual genes (cells are regulated) causes the unspecialized embryonic stem cells to become very different (cells can differentiate). The embryonic stem cells become increasingly more specialized, differentiating into a variety of cell types. Selective expression results when different parts of the genetic instructions are used in different types of cells, influenced by the cell's environment and past history.

The work of the cell is carried out by the many different types of molecules it assembles, mostly proteins. In specialized cells, other protein molecules may carry oxygen, effect contraction, respond to outside stimuli, or provide material for other body structures. In still other cells, assembled molecules may be exported to serve as hormones, antibodies, or digestive enzymes.

Learning Outcomes:
  • Explain the role of regulatory genes and how they function.
  • Explain how it is possible for different types of cells, such as bone cells and liver cells, to have identical genetic instructions and function differently.
  • Describe the role of embryonic stem cells in the development and growth of complex organisms.
  • Interpret data presented in graphs and charts from experiments addressing the role that protein-related variables (such as hormones, antibodies and digestive enzymes) play in the regulation of a complex organism’s life processes.

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