LS3.B: Variation of Traits


In this video Paul Andersen explains how variation is created in a population over time.  Variation in offspring is caused by genetic recombination, mutations and environmental effects.  Parental DNA is recombined using the process of meiosis.  Mutations can add novel genes to a population and the environment can shape the expression of genes.  A K-12 teaching progression is also included.

SEP2: Developing and Using Models

Practice 2.jpg

Paul Andersen explains the importance of modeling in science and engineering.  Models are used by scientists to explain phenomenon.  Unlike mental models, conceptual models can be shared by all scientists to improve our understanding of the Universe.  Engineers use models study systems and test designs.