[Campbell Biology P.779] The text states that in tetrapods, the head is separated from the b... | Practice Question

The text states that in tetrapods, the head is separated from the body by a neck, allowing for specific movements. If an early terrestrial vertebrate had evolved without a neck, what primary functional limitation would it likely have faced?

  • A: Difficulty in breathing air.
  • B: Inability to support body weight on land.
  • C: Restricted movement and scanning of the environment with the head.
  • D: Challenges with limb attachment to the backbone.

Explanation

The text explains: 'In tetrapods, the head is separated from the body by a neck that originally had one vertebra on which the skull could move up and down. Later, with the origin of a second vertebra in the neck, the head could also swing from side to side.' This clearly details the neck's role in providing mobility to the head for scanning the environment, which is crucial for terrestrial life. Without a neck, the head's movement would be severely limited, hindering an animal's ability to observe its surroundings for food, predators, or mates.