A student is investigating three organisms to determine patterns of common ancestry. The image shows the similarities in DNA of Organisms X, Y, and Z.
Three segments of D-N-A are labeled X, Y, and Z. Segment X shares six common D-N-A strands with segment Y. Segment X shares two common D-N-A strands with segment Z. Segments Y and Z do not share any common D-N-A strands.
The student wants to create a model to represent the relationships of the three organisms. Which cladogram should the student create?
a
A cladogram has two branches. The first branch is X. Z branches off of X. The second branch is Y.
This cladogram incorrectly shows organism X and organism Z being more closely related.
b
A cladogram has two branches. The first branch is Z. The second branch is X. Y branches off of X.
This cladogram correctly shows that the three organisms share some DNA, but that X and Y are more closely related based on the similarities in their DNA.
c
A cladogram has three branches. The first branch is X, the second branch is Y, and the third branch is Z.
This cladogram does not show that organism X and organism Y are more closely related based on the similarities in their DNA.
d
A cladogram has one branch with three branches coming off of it in the order: Y, X, then Z.
This cladogram shows all of the organisms being closely related
based on the similarities in their DNA, which is not accurate according to the information provided.
Based on the information provided, the correct cladogram to create would be:
b
A cladogram has two branches. The first branch is Z. The second branch is X. Y branches off of X.