The different types of characters.
How to identify and describe reflectional symmetry.
How to determine the types of transformations, the definition of isometry, and how to say and write a transformation's new image.
How to describe the effect of a reflection, how to describe the effect of the ordered pair rules (x,y) -> (-x, y),(x,y) -> (x, -y), (x,y) -> (y, x).
Understanding the different types of biological competition.