Flashcards in Lecture 1 Deck (22)
What are the 3 subphyla of the phylum Chordata?
What is the major characteristic of the subphylum cephalochordata?
Include Cephalochordates or lancelets. Ex: amphioxus, genus Branchiostomata
Whats the major characteristic of the subphylum Urochordata?
These include ascidians (sea squirts), thaliaceans, and larvaceans, all of which are SMALL MARINE ORGANISMS
What are the major characteristics of subphylum Vertebrata?
All the characteristics that make US Vertebrates
What are the major classes of subphylum Vertebrata??
Pisces and Tetrapods
The major class, Pisces, contains what?
contains all the fishes
What are the characteristics of the Class Agnatha?
Jawless, and lacks paired appendages.
Ex. Hagfish and freshwater lampreys
What are the characteristics of the Class Acanthodii?
"spiny sharks", not really sharks, but do have spines.
FIRST VERTEBRATES WITH JAWS
Which Class of Vertebrates does not have a jaw?
The Placodermi are known to have these two features:
jaws and paired fins.
The Chondrichthyes have these characteristics:
lack ability to form bone, skeletal system is made entirely of cartilage.
Related to sharks, skates, and rays
Largest number of species of fishes, They have a skeletal system formed from bone, but many still retain a considerable amount of cartilage w/in their sk. system
What makes the Class Mammalia different from the other Tetrapod classes?
presence of hair and mammary glands
Class Aves have what special feature?
What are the characteristics of phylum Chordata that may be shared with members of the invertebrate phyla?
2. complete digestive tract
3. Bilateral symmetry
6. Eucoelomate body cavity
7. Closed circulatory system
Big Three (four) chordate characteristics:
1. Dorsal hollow nerve chord
2. Pharyngeal "gill" slits, arches and pouches
4. Post-anal tail
**Don't have to be present in the adult, but must be present in the embryo or larva.
Major characteristics of subphylum vertebrata
1. vertebral column **ONLY FOUND IN VERTEBRATES
Why would the notochord be retained to some degree in vertebrates such as fishes and salamanders?
Because it allows for more flexibility and undulating movements of swimming.
where can the remnants of the notochord be found in humans?
Nucleus Pulposus, part of the vertebral disk system.
All modern vertebrates except ____________ have two pairs of appendages
Three basic differences between the three chordate subphyla: