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 Interdependence of Life SciPack. It explores species relationships.

All organisms, both land-based and aquatic, are interrelated by their need for resources. One example of a network of interconnections is called a food web; it is a model of the interdependence among the organisms in populations of different species. Predator-prey and parasitic relationships are examples of interspecies relationships, interdependence that occurs among organisms in different species in a food web.

Interspecies relationships can be categorized as positive, negative, or neutral for the fitness of the individuals and their populations who are involved. A change in the population of one species can affect the population of another species. Intra-species relationships, or interdependence among organisms of the same species, can also affect a population.

Learning Outcomes:

• Given the specific nature of an interspecies relationship, categorize the relationship between two interrelated populations as positive, negative or neutral for each population.
• Given a description of a change to one population depicted in a food web, predict changes that might occur in the size and rate of growth for other populations depicted in the food web.
• Given a line graph displaying changes in population sizes and rates of growth for a number of populations in a community, along with a description of the trophic relationships among populations, generate plausible hypotheses about causes of the changes depicted in the graph.

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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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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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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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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 Cell Division and Differentiation SciPack. It discusses the basics of cell division, the cell cycle, and how cells continue from one generation to the next.

Cells carry on the many functions needed to sustain life, including cell growth and development. The genetic information encoded in DNA molecules provides instructions for assembling protein molecules, which are both necessary for producing more cells and performing other cellular functions. Before a cell divides, the instructions are duplicated so that each of the two new cells gets all the necessary information for carrying on. Complex interactions among the different kinds of molecules in the cell cause distinct cycles of activities, including cell growth and division. Cell activity can also be affected by molecules from other parts of the organism, or even other organisms. Cells in multi–cellular organisms repeatedly divide to make more cells for growth and repair. Without cell division the surface area to volume ratio that constrains the size of single cells would limit an organism’s growth. Cell division in single–cell organisms makes asexual reproduction possible. Changes in DNA (mutations) occur spontaneously at low rates. Some of these changes make no difference to the organism, whereas others can change cells and organisms. In multi–cellular organisms, uncontrolled cell division, called cancer, can be caused by gene mutation. Exposure of cells to certain chemicals or radiation increases mutations and thus increases the chance of cancer.

Learning Outcomes:

• Describe the cellular events related to genetic material that must occur for cell division leading to growth or repair in multicellular organisms.
• Interpret the results of experimental variables, both internal and external to the cell, affecting cellular growth and division displayed within an experiment’s graphs or data charts.
• Compare and contrast normal, healthy cell division and cancer.
• Explain at the cellular level how recommendations for cancer prevention (i.e. smoking cessation) might influence and affect incidents of cancer.

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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 Nature of Light SciPack. It provides conceptual and real world understanding of the idea that waves (including sound and seismic waves, waves on water, and light waves) have energy and can transfer energy when they interact with matter. Wave behavior can be described in terms of how fast the disturbance propagates, and of the distance between successive crests or troughs of the wave (the wavelength). Accelerating electric charges produce electromagnetic waves which can be organized into a spectrum of varying wavelengths (and frequencies): radio waves, microwaves, radiant heat or infrared radiation, visible light, ultraviolet radiation, x-rays, and gamma rays. These wavelengths vary from radio waves (the longest) to gamma rays (the shortest). Human eyes only respond to a narrow range of wavelengths of electromagnetic radiation—what we call visible light. In empty space, electromagnetic waves of all wavelengths move at the same speed—the "speed of light."
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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 Solar System SciPack. It explores the hypothesis that the solar system coalesced out of a giant cloud of gas and debris left in the wake of exploding stars about five billion years ago. Everything in and on the earth, including living organisms, is made of the material from this cloud. As Earth and the other planets formed, the heavier elements fell to their centers. On planets closer to the Sun (the inner planets), the lightest elements and their compounds were mostly blown or boiled away by radiation from the newly formed sun. However, on the outer planets, the lighter substances still surround them as deep atmospheres of gas or as frozen solid layers.
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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 Chemical Reactions SciPack. It explains how different configurations of atoms and molecules are associated with different energy levels. Some changes of configuration among atoms and molecules require a net input of energy whereas others cause a net release. As a result, chemical reactions may release or consume energy. Some reactions such as the burning of fossil fuels release large amounts of energy by losing heat and by emitting light. Energy from light and other electromagnetic radiation can initiate many chemical reactions such as photosynthesis and the evolution of urban smog. The behavior of atoms in chemical reactions demonstrates the conservation of matter: When the number of atoms in a closed system stays the same, their total mass remains constant no matter how they are rearranged.
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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 Electric and Magnetic Forces SciPack. It explores the ability of electrons to flow, producing an electric current. Negative charges, being associated with electrons on the outer edges of atoms, are far more mobile in materials than positive charges located in the nucleus at the center of an atom. In some materials, such as metals, electrons flow easily, whereas in insulating materials such as glass they can hardly flow at all. At very low temperatures, some materials become superconductors and offer no resistance to the flow of current. In between these extremes, semi-conducting materials differ greatly in how well they conduct, depending on their exact composition. Electric currents occur when charges move through conductors. Batteries and other devices store electrical energy by separating and concentrating charges. Electrical circuits provide a means of transferring electrical energy into other forms of energy such as heat, light, and sound.
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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 five Science Objects in the Plate Tectonics SciPack. It provides a conceptual understanding of what plates are and how they move, contributing to a constantly changing surface. The Earth’s continents and ocean basins are made up of plates consisting of the crust and the upper part of the mantle. One plate can consist of both continental and oceanic crust. These plates move very slowly (an inch or so per year) on the hot, deformable layer of the mantle beneath them. The outward transfer of Earth’s internal heat drives convection circulation in the mantle. This convection, together with gravitational pull on the plates themselves, causes the plates to move.
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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 Nature of Light SciPack. It provides conceptual and real world understanding of how the wavelengths of electromagnetic radiation affect the way they interact with different materials. We perceive differences of wavelength within the visible part of the spectrum as differences in color. Shorter wavelengths of light (blue) are scattered more by air molecules than longer wavelengths of light (red). When the atmosphere scatters sunlight—which is a mixture of all wavelengths—short-wavelength light (which gives us the sensation of blue) is scattered much more by air molecules than long-wavelength (red) light is. The atmosphere, therefore, appears blue and the sun seen through it by un-scattered light appears reddened. Also, materials that allow one range of wavelengths to pass through them may completely absorb others. For example, some gases in the atmosphere, including carbon dioxide and water vapor, are transparent to much of the incoming sunlight but absorb the infrared radiation from the warmed surface of Earth.
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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 Resources and Human Impact SciPack. It explores how human activities, such as reducing the amount of forest cover, increasing the amount and variety of chemicals that enter the atmosphere, intensive farming and fishing, and consuming fossil fuels have changed Earth’s land, oceans, and atmosphere. Although the land, atmosphere, and the oceans have a limited capacity to absorb wastes and recycle materials naturally, humans have disrupted these natural cycles. Fresh water, limited in supply, is essential for life and most industrial processes. Overuse and pollution of rivers, lakes, oceans, and groundwater reduces the availability and suitability of these resources for all organisms. Technology used in the extraction and consumption of fossil fuels needed to meet the growing human demand has increased the depletion of nonrenewable energy resources such as fossil fuels, and degraded or altered the environment, both locally and globally.
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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 five Science Objects in the Plate Tectonic SciPack. It identifies the events that may occur and landscapes that form as a result of different plate interactions. The areas along plate margins are active. Plates pushing against one another can cause earthquakes, volcanoes, mountain formation, and very deep ocean trenches. Plates pulling apart from one another can cause smaller earthquakes, magma rising to the surface, volcanoes, and oceanic valleys and mountains from sea-floor spreading. Plates sliding past one another can cause earthquakes and rock deformation.
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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 fifth of five Science Objects in the Universe SciPack. It provides understanding of how the universe formed, how it has changed over time, and how it continues to change today. The ‘big bang’ theory of universe formation is supported by recent observations of the motion of galaxies, as well as observations of the energy left over from the formation of the universe. This evidence suggests that the origin of the universe occurred approximately 13.6 billion years ago, during a point in time when the state of the universe was much hotter and more dense. The fact that light seen from almost all distant galaxies has longer wavelengths than comparable light here on earth provides evidence that the whole universe has been expanding ever since the big bang (and continues to expand today).
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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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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 four Science Objects in the Interdependence of Life in Ecosystems SciPack. It explores organisms and their environments.

All organisms, including human beings, live within and depend on the resources in their environment. These resources include both living (biotic) factors such as food and nonliving (abiotic) factors such as air and water. The size and rate of growth of the population of any species, including humans, are affected by these environmental factors. In turn, these environmental factors are affected by the size and rate of growth of a population. Populations are limited in growth to the carrying capacity of the ecosystem, which is the amount of life any environmental system can support with its available space, energy, water, and food.

Learning Outcomes:

• Identify and describe biotic and abiotic factors that influence the size and growth rate of a specific population in a particular environment.
• Describe possible immediate and long-term effects on an individual population that exceeds the carrying capacity of its environment.
• Given a line graph displaying an individual population size and its rate of growth, infer the carrying capacity of the environment for that population.

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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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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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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 four Science Objects in the Cell Structure and Function SciPack. It explores the difference between living and non-living things as it looks at the many different types of cells. All self-replicating life forms are composed of cells,-from single-celled bacteria to elephants, with their trillions of cells. Although a few giant cells, such as hens' eggs, can be seen with the naked eye, most cells are microscopic. Multi-celled organisms are composed of many tiny microscopic cells, as opposed to fewer larger cells. Surface area to volume ratio makes efficient food absorption and waste removal possible in cells.
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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 five Science Objects in the Plate Tectonics SciPack. It explores the characteristics of the various layers of the Earth, using the way waves travel through the different layers to illustrate the differences in each layer. The interior of the earth is hot, under high pressure from gravitational pull, and more dense than its rocky outer crust. The earth is layered with a relatively thin crust; hot, deformable mantle; liquid outer core; and solid, metallic, and dense inner core.
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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 Cells and Chemical Reactions SciPack. It investigates the process of photosynthesis and the chemical reactions that take place in plant cells.

Photosynthesis involves unique synthesis chemical reactions in which energy from the sun is transferred into energy in the chemical bonds that are formed when smaller molecules are combined to synthesize complex molecules. For nearly every living organism on Earth, the energy required by its cells originally comes from the sun and the only way to transfer light energy into living systems is through photosynthesis. Only those organisms with chlorophyll, such as plants, can capture energy by absorbing light and using it to form strong (covalent) chemical bonds between atoms of carbon-containing (organic) molecules through photosynthesis. Plants have chlorophyll contained in chloroplasts (the site of photosynthesis) where energy rich organic compounds are synthesized for use by the plant as a source of matter and energy necessary for life. This process of photosynthesis provides a vital connection between the sun and the energy needs of nearly all living systems, and also releases oxygen to the environment.

The simple carbohydrates produced during photosynthesis can be decomposed immediately to supply matter and energy needed for metabolic processes by plants or other photosynthesizing organisms. In addition, the energy from the decomposition can be used to build other complex carbon-based molecules that help the plant grow and function (including proteins, lipids and more complex carbohydrates).
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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 four Science Objects in the Energy SciPack. It provides a conceptual and real-world understanding of the different types of energy. Energy can appear in many different forms, however all forms of energy can be broadly classified as one or a combination of two kinds: kinetic energy, which is the energy of motion; and potential energy, which depends on the relative position or shape of an object. Other kinds of energy include gravitational energy (the separation of mutually attracting masses), thermal energy (the disorderly motion of atoms or molecules), and chemical energy (the arrangement of atoms).
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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 Nutrition SciPack. It discusses how the body makes use of foods’ nutrients, after food is digested into simpler substances. These simpler substances must then be absorbed through the lining of the small intestine and transported for use throughout the body for physiological processes. In cells, these nutrients and substances derived from them are taken in and react to provide the biochemical constituents needed to synthesize other molecules. Some cells store energy from the breakdown of some nutrients in specific chemicals that are used to carry out the many functions of the cell. The circulatory system moves substances to the cells and removes waste products. Lungs take in oxygen for metabolism and eliminate the carbon dioxide produced, excretory systems rid the body of dissolved and solid waste products, and the skin and lungs rid the body of excess heat energy.
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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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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 four Science Objects in the Cells and Chemical Reactions SciPack. It investigates the basics of cellular metabolisms in plants and animals.

Chemical reactions occur in all cells, are fundamental to cell functions, and are essential to maintain the chemical and physical organization of living systems. All living organisms engage in metabolic processes that take place inside their cells. Metabolism refers to all of the chemical activities and reactions in cells and organisms that are necessary for life. Metabolic processes can be categorized into two types, which are distinguished by their function in growth and maintenance of living cells: synthesis, chemical reactions that use energy to synthesize large and complex carbon-based molecules from smaller molecules; decomposition, chemical reactions that release energy from chemical bonds by decomposing the large molecules into smaller, simpler and lower-energy molecules. The energy released in decomposition is used to synthesize large molecules and in other cellular work, including: movement, maintenance and organization, transport of molecules, and transmission of nerve impulses. A large set of protein catalysts, called enzymes are required for both synthesis and decomposition chemical reactions. Because all matter tends toward disorganized states, constant input of energy is required by all cells to maintain chemical and physical organization. Without this organization, cells and organisms die, and with death (the cessation of energy input) living systems rapidly disintegrate.
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