In what respect do hominins differ from all other anthropoids?

• A. Hominins lay eggs rather than giving birth to live young.
• B. Hominins have prehensile tails for grasping branches.
• C. Hominins are bipedal, walking upright on two legs.
• D. Hominins possess a cloaca instead of separate openings for excretion and reproduction.

Answer: (C)

Verified step by step guidance

1. Understand the term 'hominins': Hominins refer to a group of species that includes modern humans and our closest extinct relatives, such as Australopithecus and Homo species. They are distinct from other anthropoids, which include monkeys and apes.
2. Review the key traits of anthropoids: Anthropoids are primates that include monkeys, apes, and humans. Most anthropoids are quadrupedal (walking on four limbs) and lack the specialized adaptations seen in hominins.
3. Identify the unique trait of hominins: Hominins are characterized by bipedalism, which means walking upright on two legs. This adaptation is a defining feature that sets them apart from other anthropoids.
4. Eliminate incorrect options: Hominins do not lay eggs (they are mammals and give birth to live young), do not have prehensile tails (a trait seen in some monkeys), and do not possess a cloaca (a feature found in birds and reptiles).
5. Conclude with the correct answer: The unique feature of hominins is their ability to walk upright on two legs, which is a key evolutionary adaptation for this group.