Which statement best summarizes the sequence data for the VB gene?
The Coughing Frog
Carl Kauffeld was a world-renowned and well-respected expert in Reptile and Amphibian biology. In 1937, he was doing
a field study in rural Connecticut when he heard an unusual noise. In his notes, he recorded that he heard a number of
coughs from the swamp he was in. He feared he had stumbled upon a pond full of sick frogs. He was able to scoop up
one of the coughing frogs and brought it to his lab to study. As it turned out, his new little friend was not sick, but
instead had a unique new mating call or “croak” that had not been catalogued or heard before.
Since a female of a particular frog species will only mate with a male who emits the correct croak, it was obvious to
Kauffeld that he had discovered a new species of amphibian. He wanted his coughing frog to be recognized as such.
His colleagues counterclaimed that it was not its own species, but instead was a mutated member of either the
Southern or Northern Leopard frog family. Kauffeld had no other evidence to show, so the idea of the little frog getting
his own scientific name was dropped.
Flash forward to today and the coughing frog is back in the news. He has been re-discovered in State Island by a
doctoral student who believes he has the proper evidence to prove the little guy indeed deserves his own genus and
Use the information below, as well as all the other collected data to answer this question.
Upon review of the scientific literature, the doctoral student discovers that there are two coding DNA sequences, known as genes, which lead to the making of proteins key to any frog being able to produce its characteristic croak. One gene product, called VB, allows for proper construction of the tissue that allows the frog to produce the croak. Another gene, called PC, adds a protein compound to the tissue which changed the pitch of the croak, giving each individual species its own particular sound, allowing the finding of a mate to be made easier.
This information sends the doctoral student back to the lab to begin another study. He obtains DNA from the coughing frog, Northern Leopard Frog, and Southern Leopard Frog. This time he uses a DNA sequencer to obtain the order of the nitrogen bases for both the VB and PC genes in each of the frogs. This allows him to obtain the following data:
|Organism||VB Gene Partial DNA Sequence|
|Northern Leopard Frog||ATGCCCTTAAACGCTACT|
|Southern Leopard Frog||ATGCCCTTAAACGCTACT|
|Organism||PC Gene Partial DNA Sequence|
|Northern Leopard Frog||GCGTAGATGGTTTTACCT|
|Southern Leopard Frog||GCGAAAATGGTTTTACCT|
Key: A=Adenine, T=Thymine, G=Guanine, C=Cytosine