Final answer:
Australopithecus and Homo differ in brain size, sexual dimorphism, facial projection, and tooth size.
Step-by-step explanation:
Australopithecus and Homo are two different genera within the hominin family and have several key morphological and behavioral differences. One major difference is brain size. Australopithecus had a smaller brain size relative to its body mass, similar to great apes, while Homo species had larger brain sizes, more similar to modern humans. Another difference is sexual dimorphism. Australopithecus males were much larger than females, resembling the size difference seen in modern gorillas and orangutans, while Homo species had a smaller size difference between males and females, similar to modern humans. Additionally, Australopithecus had more pronounced facial projection (prognathism) and larger teeth compared to Homo species.