HS-LS3-3

Corn Cob Sprouting in Water

Description:  This dramatic time lapse shows corn kernels sprouting over time. Each of the kernels represents a new corn plant and so corn cobs represent a wonderful organism for studying genetics. In elementary this phenomenon can be used to show what plants need to survive. In secondary students can investigate specific crosses, analyze patterns in the offspring, and could even study transposons "jumping genes".

Web Resources:  Why Is Our Corn Changing? - Next Gen Storylines, Corn Genetics - Biology4Friends, Corn Genetics - Wikipedia

 

Malaria and Sickle Cell Anemia

Description:  Sickle-cell anemia is caused by a single nucleotide mutation in the β-globin gene of red blood cells. This creates incorrectly structured proteins and red blood cells with a characteristic "sickle" shape. This harmful mutation does not affect carriers of the disease. However this mutation can be beneficial in certain areas because it offers protection from malarial infections. This phenomenon can be used in a unit on genetics or evolution.

Web Resources:  The Making of the Fittest: Natural Selection in Humans - HHMI, Sickle-cell Disease - Wikipedia

 

Galapagos Finch Evolution

Description:  When Darwin visited the Galapagos Island he collected a number of bird species that he brought back to England. He presented them to ornithologist John Gould thinking they were a variety of birds and he was told that they were all different varieties of finches. This led Darwin to speculate that a population of finches had arrived on the islands and had adapted to different climates through natural selection. However Darwin was never able to observe evolution taking place. Researchers Peter and Rosemary Grant have been observing evolution of Galapagos finches for the last 40 years. One of the most famous studies involved the change in beak depth of medium ground finches during times of drought. Birds that had small beaks were unable to open the dry seeds causing microevolution in the surviving birds.

Web Resources:  Peter and Rosemary Grant Research - Wikipedia, The Beak of the Finch - HHMI