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25 Cards in this Set

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-Sister group to chordates
-Food filtered from the water by a mucous net and transported by cilia to the esophagus. Anus empties current siphon. Some called sea squirts for water shooting through excurrent siphon.
-Bladelike shape
-Has somites, muscle segments develop from blocks of mesoderm which are found along each side of the notochord in all chordate embryos.
-Craniate, dorsal nerve cord eyes, other sensory organs and a skull. Leads to active predation.
-Two sets of hox genes.
-Neural crest, a collection of cells that appears near the dorsal margins of the closing nerual tube. Make structures like teeth, bones, etc.
-Lack jaws and vertebrate.
-Vertebral column
-Oldest vertebrates
-Jawless mouth
-Skeleton made of cartilage but no collagen. Instead a stiff protein matrix.
-Sharks, rays, chimaeras
-Jaws, mineralized skeleton
-Lateral line system, a row of microscopic organs sensitive to vibrations in the surrounding water.
-Ray-finned fishes
-Lungs or lung derivatives
-Lobed fins: prescence of rod-shaped bones surrounded by a thick layer of muscle in their pectoral and pelvic fins.
-Lobed fins
-Turtles, snakes, crocodiles, birds
-Fertilization is external, male graps female and spills his sperm over the eggs as the female sheds them. Lay eggs in water or moist land.
-Amniotic egg
-Extraembryonic membranes because they are not part of the body of the embryo itself, these membranes develop from tissue layes that grow out from the embryo.
~Allantois: disposal sac for certain metabolic wastes produced by the embryo.
~Amnion: protects the embryo, is a fluid-filled cavity that cushions against mechanical stock.
~Chorion: exchange gases between the embryo and air, oxygen and carbon dioxide diffuse freely across the shell.
~Yolk sac: a stockpile of nutrients.
-Scales prevent dehydration in dry air.
-Are ectothermic, absorption of external heat as the main source of body heat.
-Except birds are endothermic, capable of keeping body warm through metabolism
A longitudinal, flexible rod located between the digestive tube and the nerve cord. Provides skeletal support.
Dorsal, hollow nerve cord
Develops from a plate of ectoderm that rolls into a tuve located dorsal to the notochord.
Pharyngeal slits or clefts
The region posterior to the mouth is the pharynx. A series of pouches, the clefts separated by grooves forms along the sides. These clefts develop into slits which allow water entering the mouth to exit the body wihout passing through the entire digestive tract.
Muscular, post-anal tail
Provides much of the propelling forces in many aquatic species.
-Spiral valve, a corkscrew shaped ridge that increases surface area and prolongs the passage of food through the digestive tract.
-Eggs fertilized internally, but some species are oviparous, they lay eggs that hatch outside the mother's body. Other species are ovovivivparous, the retain fertilized eggs in the oviduct. A few species are viviparous, the young develop within the uterus and obtain nourishment prior to birth by recieving nutrients from the moter's blood through a yolk sac placenta, by absorbing nutritious fluid produced by the uterus, or by eating other eggs.
-Squamates: lizards and snakes.
-Tuatara: lizard-like reptiles.
-Boxlike shell made of upper and lower shields that are fused to the vertebrate, clavicles, and ribs.
-Weight saving modifications: lack urinary bladder, toothless, light skull, wings and feathers.
-Ratites are all flightless.
-Mammals characterized by temporal fenestra, a hole behind the eye socket on each side of the skull.
-Mammals found in Australia and New Guinea and are represented by one species of platypus and two species of echidnas.
-Placenta: a structure in which nutrients diffuse into the embryo from the mother's blood.
-Compared to marsupials, eutherians have a longer period of pregnancy. Young eutherians complete their embryonic development within the uterus joined to their mother by the placenta.
-Have opposable thumbs, they can touch the ventral surface pf the tip of all four finers withthe ventral surfaceof the thumb of the same hand.
-Three groups: lemurs, lorises and pottos, and tarsiers, and anthropoids, which include apes and monkeys.