Make up two clear, exam level multiple choice or short answer questions for each of the categories within subphylum Vertebrata provided below. Answer each question correctly, and use proper grammar and spelling (1/2 mark per question + 1 mark per answer).

### Jawless Fishes (Superclass Agnatha) **Question 1:** What structural feature differentiates jawless fishes from other vertebrates? **Answer:** Jawless fishes lack true jaws, having instead a circular mouth with rows of teeth. **Question 2:** Which two main classes are included in the superclass Agnatha? **Answer:** The two main classes are Myxini (hagfishes) and Petromyzontida (lampreys). --- ### Cartilaginous Fishes (Class Chondrichthyes) **Question 1:** What distinguishing characteristic do cartilaginous fishes possess instead of bony skeletons? **Answer:** Cartilaginous fishes have a skeleton made primarily of cartilage rather than bone. **Question 2:** Which sensory system, unique to many cartilaginous fishes, helps them detect electrical signals in the water? **Answer:** The ampullae of Lorenzini help cartilaginous fishes detect electrical signals. --- ### Ray-finned Fishes (Class Actinopterygii) **Question 1:** What are the primary components of the swim bladder in ray-finned fishes, and what is its main function? **Answer:** The swim bladder is mostly filled with gas and its main function is to help maintain buoyancy. **Question 2:** In ray-finned fishes, what structure is responsible for gas exchange and is located within the gill chambers? **Answer:** The gills are responsible for gas exchange within the gill chambers. --- ### Marine Reptiles and Birds (Class Reptilia/Aves) **Question 1:** What is the primary adaptation of marine reptiles that allows them to thrive in marine environments? **Answer:** The primary adaptation is their streamlined body shape for efficient swimming. **Question 2:** Which group of birds is particularly known for its ability to dive and catch fish while underwater? **Answer:** Sea birds, especially species like the penguin or the cormorant, are known for their diving abilities. --- ### Marine Mammals (Class Mammalia) **Question 1:** What adaptation do marine mammals possess for thermoregulation in cold ocean waters? **Answer:** Marine mammals have a layer of blubber that provides insulation against the cold. **Question 2:** Which group of marine mammals is characterized by having flippers and includes species like dolphins and whales? **Answer:** Cetacea is the group characterized by marine mammals with flippers, including dolphins and whales.