Vertebrates 1

Question 1

What are the four distinctive structures present in all chordates?

Answer 1

Notochord, dorsal hollow nerve cord, pharyngeal gill slits, post-anal tail.

Question 2

What are tunicates, and what happens to their tails and notochords as they mature?

Answer 2

Tunicates are marine organisms that lose their tails and notochords as they mature, becoming sessile filter feeders.

Question 3

What are lancelets, and how do they feed?

Answer 3

Lancelets are small fishlike invertebrate chordates that retain all four chordate features as adults. They feed by drawing food particles in with pharyngeal cilia.

Question 4

Define craniates and provide examples. What distinguishes them from other chordates?

Answer 4

Craniates include all chordates with a skull. Examples include hagfishes and vertebrates. They have a skull of bone or cartilage enclosing a brain.

Question 5

Describe the unique characteristics and habits of hagfishes.

Answer 5

Hagfishes lack jaws, respire using gills, secrete slime as a defense mechanism, and have a rudimentary braincase but no true backbone.

Question 6

List several key adaptations that have contributed to the success of vertebrates in diverse habitats.

Answer 6

Internal skeleton, paired appendages, jaws, increased brain complexity and sensory structures.