id 4 - MetaBlast

Guide for Using a Visual Model of the Cell in Meta!Blast

M odels such as the cellular image in Meta!Blast can have great value in the sciences and the science classroom when trying to convey information about cellular structure and function. The cell in context. Teacher should emphasize cellular processes as these contribute to a larger system.

Biology as a discipline is based on the study of systems and levels. From levels as grand as the biosphere to those as small as chemical bonding, there is a ripple effect in which events on a micro-scale can collectively build to affect the course of events on a macro-scale. In turn, macroscale events can create mass events on micro-scales. The cell is an elegant system of its own that is affected by systems and events that are much larger and smaller than it. The structure of the cell itself conveys that it is an entity of collective parts, each with its own set of functions, but the collective parts working together to serve a greater function.

An understanding of the cell hence entails a clear appreciation of these interacting and interdependent levels ranging from atomistic to holistic. In order to facilitate an understanding of the interdependence of systems in biology, a logic of analyzing biological phenomena from a macro-scale to a micro-scale should be attempted.

Using models and comparisons to explain biological phenomena that cannot be sensed directly. Concepts in cellular biology can be illustrated through the use of analogies. Educators frequently use analogies to understand science phenomena, and to convey that understanding to others (Glynn, 2008; James & Scharmann, 2007). Many times analogies are used in relation to the systematic nature of cellular structure and function to try to illustrate how individual parts of the cell have their own function, but also work together to serve a greater purpose. One of the more widely used analogies for cells is that of a factory (Glynn, 2007). In this analogy, organelles take on meaning as parts of a factory. For instance, the control center of the factory or supervisor would be the nucleus, the power plant would be the mitochondria.

Another common analogy-based lab outlined in Glynn (2007) is the creation of edible cell models out of foods such as gelatin for cytoplasm and candies as the organelles. Analogies and other comparisons can be useful, but if extended too far can be confusing to a student that wants to understand biology in more depth (for example, in a photosynthetic cell there are two major “power houses”, the mitochondria and the chloroplasts; as another example “photosynthesis is the opposite of respiration” is true only to a point).

Using models effectively

Teachers are the most important component in determining whether education is effective. This means that regardless of the model, strategy, analogy, etc. the role of the teacher is crucial to the understanding of the concepts the student develops (Berliner 1989; Olson and Clough 2001; Penick et. Al 1986). Science educators at grade 8-graduate school level must first familiarize themselves with content, including new scientific discoveries. This is particularly true for biology, which because of multiple technological innovations and the potential for novel applications, is a very fast-moving field. Teachers should then diagnose student understanding of the target concept and work to strengthen correct concepts and dispel misconceptions. Teachers can begin to diagnose students’ thinking in the exploration phase of the learning cycle prior to models or analogies being presented.

Once teachers have diagnosed students’ thinking and are ready to address concepts through models, they should convey the role of models in science to students. The roles of models in science and science education are described by Cullen and Crawford (2002) and Grosslight et al. (1991):

  1. Modeling in science is an essential aspect of scientific inquiry.
  2. The purpose of the model dictates in some way the form or representation of the model.
  3. Models are tentative and based on experimental evidence and may be modified, replaced, or disposed of based on new evidence.
  4. Models are theory based and are representations of ideas of the reality of the natural world, not the reality of the natural world itself.
  5. Models can vary from reality in many ways including size, temporal consideration, and structure.
  6. Different models of the same phenomena can represent different theoretical views of the model.
  7. In addition to communicating information, models are primarily used to test and develop ideas and knowledge of the natural world, many times possessing variables or manipulatives that can be changed to better understand phenomena.
  8. Models are not always concrete or physical in nature, but also take conceptual form.

Actual strategies and considerations for conveying an accurate portrayal of models in science can be found in the document: Biological Models Lab 2010 by Iowa High School biology teachers Craig Walter and Katherine Larson.

Guide to structure in Meta!Blast

Students should be shown the overall plant they will be playing Meta!Blast in prior to the actual cell. While showing them this virtual plant, teachers may want to have a plant handy, for reference to a real world analogy. Questions to be posed can include:

  1. What is necessary for the Meta!Blast plant and other plants to survive?
  2. Why is it so essential for animals that plants in Meta!Blast is saved?
  3. How are this real plant and the virtual Meta!Blast plant similar? How are they different?
  4. What do you notice about the structure of the real and virtual plant as you zoom in?
  5. How do these structures lend to the idea that a plant is a system made up of smaller systems?
  6. How do these structures lend to the idea that a plant is a system that are part of larger systems?