Campbell Biology 11th Edition by Lisa Urry,Michael Cain,Steven Wasserman,Peter Minorsky,Jane Reece

Exercise 16

Are you a victim of fish fraud
When buying salmon, perhaps you prefer the more expensive wild-caught Pacific salmon ( Oncorhynchus species) over farmed Atlantic salmon ( Salmo salar ). But studies reveal that about 40% of the time, you aren't getting the fish you paid for! Watch the video in the MasteringBiology Study Area for more information.
ABC News Video: Fake Fish in Stores and Restaurants
Instructors : A version of this Problem- Solving Exercise can be assigned in Chapter 5 of MasteringBiology. A more extensive investigation is in Chapter 26 of MasteringBiology.
In this exercise, you will investigate whether a piece of salmon has been fraudulently labeled.
Your Approach
The principle guiding your investigation is that DNA sequences from within a species or from closely related species are more similar to each other than are sequences from more distantly related species.
Your Data
You've been sold a piece of salmon labeled as coho salmon ( Oncorhynchus kisutch ). To see whether your fish was labeled correctly, you will compare a short DNA sequence from your sample to standard sequences from the same gene for three salmon species. The sequences are:
How many bases differ between (a) O. kisutch and your fish sample (b) O. keta and the sample (c) S. salar and the sample