9.5 Concept Maps
A concept map is way to visualize the relationship between different concepts and propositions. Figure 9.9 is a concept map of the cell cycle. A quick glance at the map reveals that the cell cycle is divided into two portions, a growth and development phase, and a division phase. The growth and development phase is subdivided into three parts, while the division phase is subdivided into four. The map shows the sequence of phases, and what each accomplishes. Although the same information could be described just with words, a concept map, which employs pictures, groupings, connections, and brief descriptions, may be a more economical and effective way to accomplish the same goals. It is easier to visualize a concept map, with an organized array of entries representing stages, than it is to visualize the same concept using only text.
Figure 9.10 is a more complex concept map, showing the relationship between various forms of energy. The rectangles identify different forms of energy, and the arrows identify the processes by which energy is transformed from one form to another. The ovals represent uses of this energy once it is distributed to homes via electricity. Note the many ways that energy may flow from the Sun to power our homes, industries, and appliances.
Both of these concept maps summarize complex processes and represent them in the form of a map. Concept maps have been shown to aid learning and memory, but the real value of concept mapping is realized when the learner develops his or her own maps. Concept maps can provide a foundation for writing reports, developing laboratory procedures, or brainstorming relationships within our complex world. Note that concept maps are not linear, but branched and intertwined because the real world is inter-connected.
Activity 9.5.1 – Developing a concept map for a complex concept - nuclear winter
Researchers have proposed that the climate of the Earth could become inhospitably cold in the event of a large-scale nuclear war. Nuclear explosions create a huge amount of dust and initiate numerous building, forest, and brush fires. These events could propel vast amounts of smoke and dust into the stratosphere, an otherwise stable layer of the atmosphere. Dust and smoke in the stratosphere could reflect much sunlight before it reaches Earth. Winds in the stratosphere could distribute the dust evenly around the Earth, causing surface temperatures to drop as much as twenty degrees Celsius due to the increased reflection of light back into space. The lack of sunlight, and resulting decrease in global temperature, could reduce the amount of photosynthesis, and thereby reduce available food and oxygen supplies, disrupting all life that depends on plants. Nitrogen oxides produced during nuclear explosions could lead to a rapid degradation of the ozone layer, and a dramatic increase in the amount of ultraviolet light reaching the surface of the Earth. Increased ultraviolet radiation could kill sensitive phytoplankton in the oceans, upsetting oceanic food chains that are dependent upon them. The complex implications of a "nuclear winter" are better understood with the use of a concept map. Re-read this paragraph and draw a concept map showing the relationship between variables and processes.
Activity 9.5.2 – Developing a concept map for a food web
Develop a concept map for a terrestrial food web with the organisms listed below. Arrows should point from food to the consumer, showing the flow of energy and nutrients.
· Primary producers: grasses, shrubs, trees
· Primary consumers: rabbits, squirrels, mice, seed eating birds, herbivorous insects
· Secondary, tertiary and quaternary consumers: spiders, predaceous insects, insectivorous birds, toads, snakes, foxes, hawks, owls
· Detritivores: millipedes, collembola, detritivore beetles
· Decomposers: fungi, bacteri
Activity 9.5.3 – Developing concept maps to trace the invention of new technologies
History records that Thomas Edison invented the light bulb, Alexander Graham Bell, the telephone, and Jonas Salk, the polio vaccine. Although they deserve credit for their inventions, it should be noted that these men were successful only because they were able to connect the ideas of others. For example, to invent the light bulb, Edison had to connect the technologies and findings (highlighted in italics) of many who preceded him, as the following paragraph details.
At the base of a light bulb are two electrodes that connect to opposite ends of a thin metal filament suspended in a glass bulb filled with an inert gas such as argon. When connected to a power supply, an electric current flows through the thin filament, which heats up due to its small width and high resistance. The filament glows when it reaches a certain temperature, but does not ignite because of the inert atmosphere in the bulb. To invent the light bulb, it was necessary to tie together the following inventions and discoveries: electricity, battery or power supply, electrical conductors, glass, argon or other inert gas, and a carbon or tungsten filament.
Develop a concept map that shows how prior discoveries or inventions were essential to the development of the light bulb or other invention.
Activity 9.5.4 – Developing your own concept maps.
Develop a concept map for a topic of your own interest or one of the options that follows. Choose a theme that has many possible connections such as:
heart rate regulation
blood sugar regulation
human life cycle
alternation of generations
PCR (polymerase chain reaction)
physical & earth sciences
energy balance of Earth
electricity - sources and uses
from oil to plastics
water purification and treatment