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Classroom Resource
Milk—How Sweet Is It?


In this lab, students test different samples to see which ones contain the lactase enzyme.

A hands-on activity in which students simulate a lactose tolerance test similar to the one shown in the film. Students will combine milk with "patients' intestinal fluid samples," which consist of either water or a lactase solution. They then measure the amount of glucose produced over time. Students will collect, analyze, and graph their data to determine which patients are lactose tolerant or lactose intolerant. 

Note: This lab was initially posted in June 2013 and updated April 2015 to incorporate feedback from field testers.

Curriculum Connections:

HS-LS1-3, HS-LS3-1, HS-LS4-1, HS-LS4-2, HS-LS4-3, (LS4.B, LS4-C), HS-LS4-5

Common Core*
CCSS.ELA-Literacy.RST.9-10.3, CCSS.ELA-Literacy.RST.9-10.4

AP (2012-13 Standards)
2.D.3, 2..D.4, 3.A.1, 3.C.1, 4.A.1, 4.A.4, .4.B.1, 4.B.2

IB (2009 Standards)
3.2, 3.5, 3.6, 6.1, 7.3, 7.4, 7.5, 7.6, A2, A3, C1, C2, D3, H3

Supporting Materials (6)

Classroom Resource
Students explore the genetic changes associated with lactose tolerance/intolerance and how the trait is inherited in families.
Classroom Resource
Students evaluate and discuss several statements about lactose intolerance and evolution before and after watching the film.
Classroom Resource
Students explore the effects of different diets on the evolution of an enzyme that breaks down starch.
Classroom Resource
Students interpret the results of two different tests for lactase persistence.
Short Film
Follow human geneticist Spencer Wells, Director of the Genographic Project of the National Geographic Society, as he tracks down the genetic changes associated with the ability to digest lactose as adults, tracing the origin of the trait to less than 10,000 years ago, a time when some human populations started domesticating animals.
Film Guides
The following classroom-ready resources complement Got Lactase? The Co-evolution of Genes and Culture, which tells the story of the evolution of the ability to digest lactose, a genetic trait that arose in humans within the last 10,000 years in some pastoralist cultures.

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