A doe burst out of the forest and tore across the meadow, two wolves in close pursuit. This drama unfolded not twenty feet from where my young daughters and I knelt in our garden peacefully pulling weeds, our pant legs wet with morning dew. In less than two heartbeats they pierced the deep wood on the far side of the meadow, leaving a wake of quaking vegetation. We live at the base of a mountain in northwestern Montana.
The next concept—scale, proportion, and quantity—concerns the sizes of things and the mathematical relationships among disparate elements.
The next four concepts—systems and system models, energy and matter flows, structure and function, and stability and change—are interrelated in that the first is illuminated by the other three. Each concept also stands alone as one that occurs in virtually all areas of science and is an important consideration for engineered systems as well.
Regardless of the labels or organizational schemes used in these documents, all of them stress that it is important for students to come to recognize the concepts common to so many areas of science and engineering.
Patterns Patterns exist everywhere—in regularly occurring shapes or structures and in repeating events and relationships. For example, patterns are discernible in the symmetry of flowers and snowflakes, the cycling of the seasons, and the repeated base pairs of DNA.
Noticing patterns is often a first step to organizing and asking scientific questions about why and how the patterns occur.
One major use of pattern recognition is in classification, which depends on careful observation of similarities and differences; objects can be classified into groups on the basis of similarities of visible or microscopic features or on the basis of similarities of function.
Such classification is useful in codifying relationships and organizing a multitude of objects or processes into a limited number of groups. Patterns of similarity and difference and the resulting classifications may change, depending on the scale at which a phenomenon is being observed.
For example, isotopes of a given element are different—they contain different numbers of neutrons—but from the perspective of chemistry they can be classified as equivalent because they have identical patterns of chemical interaction. Once patterns and variations have been noted, they lead to questions; Page 86 Share Cite Suggested Citation: A Framework for K Science Education: Practices, Crosscutting Concepts, and Core Ideas.
The National Academies Press. Engineers often look for and analyze patterns, too. For example, they may diagnose patterns of failure of a designed system under test in order to improve the design, or they may analyze patterns of daily and seasonal use of power to design a system that can meet the fluctuating needs.
The ways in which data are represented can facilitate pattern recognition and lead to the development of a mathematical representation, which can then be used as a tool in seeking an underlying explanation for what causes the pattern to occur.
For example, biologists studying changes in population abundance of several different species in an ecosystem can notice the correlations between increases and decreases for different species by plotting all of them on the same graph and can eventually find a mathematical expression of the interdependences and food-web relationships that cause these patterns.
Progression Human beings are good at recognizing patterns; indeed, young children begin to recognize patterns in their own lives well before coming to school.
They observe, for example, that the sun and the moon follow different patterns of appearance in the sky.
Once they are students, it is important for them to develop ways to recognize, classify, and record patterns in the phenomena they observe.
For example, elementary students can describe and predict the patterns in the seasons of the year; they can observe and record patterns in the similarities and differences between parents and their offspring.
Similarly, they can investigate the characteristics that allow classification of animal types e. These classifications will become more detailed and closer to scientific classifications in the upper elementary grades, when students should also begin to analyze patterns in rates of change—for example, the growth rates of plants under different conditions.
By middle school, students can begin to relate patterns to the nature of microscopic and atomic-level structure—for example, they may note that chemical molecules contain particular ratios of different atoms. Thus classifications used at one scale may fail or need revision when information from smaller or larger scales is introduced e.
Mechanism and Prediction Many of the most compelling and productive questions in science are about why or how something happens.
Today infectious diseases are well understood as being transmitted by the passing of microscopic organisms bacteria or viruses between an infected person and another.
A major activity of science is to uncover such causal connections, often with the hope that understanding the mechanisms will enable predictions and, in the case of infectious diseases, the design of preventive measures, treatments, and cures. Repeating patterns in nature, or events that occur together with regularity, are clues that scientists can use to start exploring causal, or cause-and-effect, relationships, which pervade all the disciplines of science and at all scales.
For example, researchers investigate cause-and-effect mechanisms in the motion of a single object, specific chemical reactions, population changes in an ecosystem or a society, and the development of holes in the polar ozone layers. Any application of science, or any engineered solution to a problem, is dependent on understanding the cause-and-effect relationships between events; the quality of the application or solution often can be improved as knowledge of the relevant relationships is improved.
Identifying cause and effect may seem straightforward in simple cases, such as a bat hitting a ball, but in complex systems causation can be difficult to tease out. It may be conditional, so that A can cause B only if some other factors are in place or within a certain numerical range.
For example, seeds germinate and produce plants but only when the soil is sufficiently moist and warm. Frequently, causation can be described only in a probabilistic fashion—that is, there is some likelihood that one event will lead to another, but a specific outcome cannot be guaranteed.
For example, one can predict the fraction of a collection of identical Page 88 Share Cite Suggested Citation: One assumption of all science and engineering is that there is a limited and universal set of fundamental physical interactions that underlie all known forces and hence are a root part of any causal chain, whether in natural or designed systems.If a predator switches between prey A and B on the basis of their frequency, it will eat A when B is rare and B when A is rare.
The prey should exhibit mild oscillations, and the predator should fluctuate little. Predator-Prey There many examples of predator-prey relationships: wolves eating rabbits, frogs eating insects, even a goat eating grass.
Grass could be considered the prey. Pursuit predation is the form of predation in which predators give chase to fleeing prey. The chase can be initiated either by the predator or by the prey, should the prey be alerted to a predator's presence and attempt to flee before the predator gives chase.
Predator-prey relationships make possible the rich biodiversity of complex ecosystems whether it is a predator-prey relationship, a mutualistic relationship or a competitive relationship.
Evolution home: Predator-Prey Relationships. A predator is an organism that eats another organism.
The prey is the organism which the predator eats. Some examples of predator and prey are lion and zebra, bear and fish, and fox and rabbit.
Jan 13, · Best Answer: A predator-prey relationship describes a biological interaction where a predator feeds on a prey.
The predator is the organism that kills and feed on other organisms; the organisms that are eaten are called the pfmlures.com: Resolved.
Significant Energy E vents in Earth's and Life's History as of Energy Event. Timeframe. Significance. Nuclear fusion begins in the Sun. c. billion years ago (“bya”) Provides the power for all of Earth's geophysical, geochemical, and ecological systems, with . Fulfillment by Amazon (FBA) is a service we offer sellers that lets them store their products in Amazon's fulfillment centers, and we directly pack, ship, and provide customer service for these products. If a predator switches between prey A and B on the basis of their frequency, it will eat A when B is rare and B when A is rare. The prey should exhibit mild oscillations, and the predator should fluctuate little.