Vertebrates 1 Flashcards
(32 cards)
Name 3 characteristics that are unique to chordates?
- Dorsal Hollow Nerve Chord
- Notochord(long, rigid, fluid filled sheet that provides structure to the organism)
- Muscular, post-anal tail
Are chordates deuterostomes or protostomes?
Deuterostomes
What is a characteristic shared by all deuterostomes?
Pharyngeal Slits. Pouches located on the side of the head supported by pharyngeal arches. Lost in echinoderms. Similar structures can be found in humans ears and jaws
What type of feeding do fish do?
Filter feeding
How do pharyngeal slits work for food?
Water enters the mouth of the chordate and then exits out of the pharyngeal slits. As it exits the pharyngeal slits filter food out of the water.
How do pharyngeal slits work for reparation?
Water enters through the mouth and exits through the pharyngeal slits. As it exits O2 and CO2 are exchanged across the respiratory surface(gills)
Key Feature of vertebrates: Axial Skeleton
-Cranium(skull)
-Vertebral Column(spine)
-Ribs
Key feature of vertebrates: Appendicular Skeleton
-Pectoral girdle(arms)
-Pelvic girdle(legs)
Do vertebrates have opened or closed circulatory systems?
Closed(within vessels). Ventral heart
Key feature of vertebrates: Organs in coelom
Sac where organs are suspended
Another word for pharyngeal slits
Gill slits
Gill arches
-made up of cartilage and bone and support the gills
How gills exchange gasses?
O2 enter the mouth in the water and the water then passes over the gills. The gills filter out O2 as wells as food and CO2 and other waste is put back into the water
Operculum
covers and protects the gills
Why is it important the gill filaments are thin?
Gill filaments contain capillary beds that are used to exchange gases by having thin gill filaments this eases diffusion
How is O2 brought into the blood vessels of the gill arches?
Water comes through the mouth of the fish and then passes over its gills including its gill filaments. Gill filaments contain capillary beds that are connected to the blood vessels in the gill arches. When the oxygenated water passes over the filaments the O2 is diffused into the capillary beds and then brought to the rest of the fish
Why is counter current exchange important for diffusion of O2?
Things like to flow from high concentration to low concentration. By having the water and blood flowing in opposite directions the water will always have more oxygen in it than the blood, so this results in more efficient exchange because O2 will constantly be flowing into the blood.
Why is concurrent exchange inefficient?
When flowing the same direction the blood and water will eventually have the exact same amount of O2 in both of them. This will cause the gas exchange to stop because there is no longer a concentration gradient forcing the O2 to diffuse into the blood.
Fish circulatory system
-Fish have closed circulatory systems
-Deoxygenated blood goes to the gills via arteries - blood is then oxygenated in the gills and is distributed among the body and then deoxygenated blood with CO2 is brought back to the gills
-Heart only has 2 chambers
Are fish monophyletic?
NO(not a true evolutionary group)
Examples of jawless fish
Hagfish, lamprey
How do hagfish eat?
Hagfish tie a a knot in their tail and then move the know down their body till it reaches their head. Once at their head they will pull against the knot to pull pieces of food off the body
how do lamprey eat?
Lamprey have an oral disc and they latch onto fish and suck juices from them
Gnathostomes
Jawed fishes
