BasicStudents matched to this level have a partial mastery of prerequisite knowledge and skills fundamental for proficient work.
At Grade (Proficient)Students matched to this level have demonstrated competency over challenging subject matter, including subject matter knowledge, application of such knowledge to real-world situations, and analytical skills appropriate to subject matter.
AdvancedStudents matched to this level are ready for material that requires superior performance and mastery.
Illustrates a problem that can occur during gametogenesis. Down's syndrome arises when two sister chromatids fail to separate during the final stages of meiosis. Start at 1:10 if you just want to see the nondisjunction.