NSTA RSS Feeds 

Search Results

Cells and Chemical Reactions: Basics of Metabolism Science Object
Science Object
Cells and Chemical Reactions: Basics of Metabolism
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 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...  [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 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.
[hide full abstract]
Member Price: Free      Nonmember Price: Free
Cell Structure and Function: The Cellular Factory Science Object
Science Object
Cell Structure and Function: The Cellular Factory
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 second of four Science Objects in the Cell Structure and Function SciPack. It explores the various organelles within a cell and each organelle’s function. Every cell is surrounded by a membrane that separates it from the outside world. This membrane controls what can enter 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 second of four Science Objects in the Cell Structure and Function SciPack. It explores the various organelles within a cell and each organelle’s function. Every cell is surrounded by a membrane that separates it from the outside world. This membrane controls what can enter and leave the cell. Inside cells exists a variety of specialized molecular structures (organelles) that carry out such functions as energy production, transport of molecules, waste disposal, synthesis of new molecules, and the storage of genetic material. All these molecular structures function as a coordinated system that works in a delicate balance of chemical and physical reactions. In addition, most cells of multi-cellular organisms perform some special functions that other cells do not.
[hide full abstract]
Member Price: Free      Nonmember Price: Free
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.

[hide full abstract]
Member Price: Free      Nonmember Price: Free
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.

[hide full abstract]
Member Price: Free      Nonmember Price: Free
Interdependence of Life: Species Relationships Science Object
Science Object
Interdependence of Life: Species Relationships
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 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;...  [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 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.

[hide full abstract]
Member Price: Free      Nonmember Price: Free
Interdependence of Life: Organisms and Their Environments Science Object
Science Object
Interdependence of Life: Organisms and Their Environments
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 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...  [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 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.

[hide full abstract]
Member Price: Free      Nonmember Price: Free
Heredity and Variation: Mutation Provides Variation Science Object
Science Object
Heredity and Variation: Mutation Provides Variation
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 Heredity and Variation SciPack. It explores the role of mutations in genetic variation. The random combination of genes during sexual reproduction is not the only source of variation in organisms. Although some genes may be passed...  [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 Heredity and Variation SciPack. It explores the role of mutations in genetic variation.

The random combination of genes during sexual reproduction is not the only source of variation in organisms. Although some genes may be passed for many thousands of generations with no consequential changes in its function, occasionally a mutation occurs in which a gene may be altered. Gene mutations can occur spontaneously through random errors in copying, or induced by chemicals or radiation that affect the DNA’s chemical bonds. Only if a mutated gene is in a gamete is it possible for copies of it to be passed down to offspring, becoming part of all their cells, altering the nature of some proteins produced by the DNA. The function of a mutated gene may not be altered or it may have its function in protein synthesis altered, which subsequently affects the physical traits expressed in the organism. Mutations provide additional sources of variation that can be helpful, harmful or of no impact on the survival an individual.

Learning Outcomes:
  • Compare and contrast genetic mutations with genetic variations resulting from the process of meiosis.
  • Identify and describe the general processes involved in the creation of genetic mutations.
  • Describe possible consequences of genetic mutations.
  • Describe conditions necessary for genetic mutations to be inherited by an organism’s offspring.

[hide full abstract]
Member Price: Free      Nonmember Price: Free
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.

[hide full abstract]
Member Price: Free      Nonmember Price: Free
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.

[hide full abstract]
Member Price: Free      Nonmember Price: Free
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.


[hide full abstract]
Member Price: Free      Nonmember Price: Free
Results: 1 - 10 of 2027 1 2 3 4 5 6 7 8 9 ... 203 Next