Warm-Up
• Write a reminder for your project, as well as the
upcoming test date – get it stamped!
• Update your table of contents for today!
• Complete the “Before” column on the Anticipation
Guide.
Date
Session
#
1/13 &
1/14
6
Activity
Page
#
Anticipation Guide & Background Notes
13
“Milk…How Sweet Is It?” Lab Guide
14
Warm-Up/Review:
• What is a catalyst?
• What is a genotype?
• What is coevolution?
Lactose Vs. Lactase Notes
(write what is in black on the slides)
• Lactose = a sugar found only in milk
• Lactase = an enzyme found in the lining
of the small intestine that acts as a
catalyst in the breakup of lactose into
glucose, which can be digested by the
body
Just FYI…
Enzyme = a substance produced by a living
organism that acts as a catalyst to bring
about a specific biochemical reaction
Lactose Vs. Lactase
• What does lactose intolerance mean?
• So what do you think lactase persistence
means?
• These are genetic characteristics…so, do
you think that it is more likely for people to
be lactose intolerant or lactase persistent?
The Facts About Lactose Intolerance…Remember, Milk has
Sugar, Fats & Proteins:
• Lactose intolerant people cannot digest the sugar (lactose)
in milk.
• It causes diarrhea and other unpleasant symptoms 
• As a result, the milk “races through” the digestive system…
very little of the other nutrients in the milk (fat & protein)
don’t remain in the body long enough to be digested.
Milk – How Sweet Is It? Lab
• Your group will have a sample of the “intestinal
fluid” of a patient. You will test the fluid to
determine if your patient has the gene for lactase
persistence and is able to digest milk.
• Follow the lab directions and share your data with
the class by adding your data to the table on the
board.
• Answer the lab questions on your sheet.
Milk – How Sweet Is It? Lab Roles
• Group Leader – reads all directions and keeps group
on task; reinforces the jobs of others
• Supply Manager/Clean Up – manages supplies
• Math & Map Master – does calculations & is in charge
of recording math & map information (someone with
a phone)
• Discussion Leader – Leads the discussion of the
questions to share information with the group and the
class if required
Milk – How Sweet Is It? Lab Results
Samples
Patient #1
(Japan)
Patient #2
(Kenya)
Patient #3
(China)
Patient #4
(Italy)
Patient #5
(Papua New Guinea)
Patient #6
(Finland)
Patient #7
(Saudi Arabia)
Patient #8
(Uganda)
2 minutes
Glucose levels
(mg/dL)
Global Distribution
of the
Lactase Persistence Genotype
You will analyze the distribution of lactase persistence
(ability to digest milk) across a large area of the world.
1. Calculate the frequency of lactase persistence for the 3-4
regions on your strip of paper.
2. For each region, you must put a sticker on the board. If the
percentage is less than 40%, place a pink sticker, if the
percentage is equal to or greater than 40%, place a green
sticker.
= lactose intolerance
= lactase persistence
3. When you have the percentages calculated, send your
Math & Map Master to place the stickers on the correct
country on the map on the board.
1. Create a key for the map on your answer sheet.
- One color for lactase persistence (ability to digest milk ≥ 40%)
- One color for lactose intolerance (ability to digest milk < 40%)
2. Using dots or shading, duplicate the class data on the map on your
note sheet.
Global Distribution of the
Lactase Persistence Genotype
Answer the activity
questions below the
map
on your note sheet
Got Lactase?
The Co-Evolution of Genes & Culture
Got Lactase: The Co-Evolution of Genes and Culture
http://www.hhmi.org/biointeractive/making-fittest-got-lactase-co-evolution-genes-and-culture
• After the video, take the quiz again, put your answers in the “after”
column. Answer the questions following the quiz
Global Distribution of the
Lactase Persistence Genotype
Answer the reflection
questions on the back
of the video page of
your note sheet.