Final answer:
A cladogram is a phylogenetic diagram that shows the relationships among organisms, with closely related ones sharing more traits. Organisms A and B are most closely related. The green dot might represent an ancestral trait like a backbone, while the orange circle could indicate a derived trait unique to A and B, such as mammary glands.
Step-by-step explanation:
A cladogram is a branching diagram representing related organisms, which is used to show phylogenetic relationships. It indicates how organisms or groups are related through common ancestors and the emergence of new traits that differentiate one group from another. When examining a cladogram, shared traits help determine which organisms are more closely related.
- The two organisms most closely related are organisms A and B as indicated by their shared derived traits.
- The green dot which is shared by every animal could represent an ancestral characteristic such as a backbone in vertebrates.
- The trait shared by animals A and B but not by C, indicated by the orange circle, might be a derived characteristic such as the presence of mammary glands in mammals.