Vertebrates Flashcards
Chordates Characteristics
- A notochord (flexible rod located between the digestive tube and the nerve cord) that provides skeletal support
- A hollow nerve cord that is located dorsal rather than ventral to the notochord (Will develop into the central nervous system)
- Pharyngeal clefts (Grooves that separate a series of pouches along the sides of the pharynx)
- A muscular, post-anal tail
What happens in chordates such as Fish
In vertebrates such as fish, these pharyngeal clefts develop into pharyngeal slits which then develop into gill slits
What happens in chordates such as Humans
In vertebrates such as humans, these pharyngeal clefts develop into pharyngeal slits develop into parts of the ear and other structures in the head and neck
Characteristics od Craniates
Characteristics of a chordate plus:
Two clusters of Hox genes rather than only one set
A neutral crest that will disperse throughout the body to give sensory capsules in which eyes and other sense organs develop
A high metabolism and an extensive muscular system
A heart with at least two chambers, red blood cells, and hemoglobin
Kidneys that remove waste products from the blood
Example of Craniates
Hagfish
Characteristics of Vertebrates
- A more extensive skull
- Backbone composed of vertebrae
- Lack jaws
Example of Vertebrates
Lamprey
Characteristics of Gnathostomes
- Have jaws
- Four clusters of Hox Genes rather than only two sets
- An enlarged forebrain due to enhanced senses of smell and vision
- Mineral based and have a stronger endoskeleton
Examples of Gnathostomes
Chondrichthyes: Cartilaginous fishes such as sharks and rays
Actinopterygii: Bony ray finned fishes such as tuna and trout
Dipnoi: Bony lobe finned fishes such as lungfish
Characteristics of Tetrapods
- 4 limbs that can support the animals weight on land
- Feet with digits that allow the animal to transmit muscle-generated forces to the ground when they walk
- Pelvic girdle bones are fused to the backbone permitting forces generated by the hind legs against the ground to be transferred to the rest of the body
Examples of Tetrapods
Salamanders, frogs
Characteristics of Amniotes
- An amniotic egg which contains specialized membrane that function in gas exchange and protection for the embryo
- The amniotic egg of most reptiles have a shell which resists dehydration on land, white the amniotic egg of most mammals avoids desiccation by developing within the mother
- Less permeable skin and the ability to use the rib cage to ventilate the lungs
Examples of Amniotes
Birds and Reptiles
Characteristics of Mammals
- Mammary glands which produce milk for offspring
- Efficient respiratory and circulatory systems to support high metabolic rate, and hair to retain body heat
- Mammals and birds are both endothermic (bodies are warmed by heat generated by the metabolism - body temp is stable regardless of environmental temperature)
- Both mammals and birds have lungs with a large surface area for gas exchange as well as a four-chambered hearts which keeps oxygenated blood separated from deoxygenated blood
- Hair in mammals and feathers in birds help to retain body heat
- Larger brain for body size
- Increased duration of parental care (Capable of learning)
- Differentiation of teeth
Example of Mammals
Humans, cats
