Ch. 34 Flashcards
Chordates are bilaterian animals that belong to the clade of animals known as ________.
Deuterostomia.
Chordates comprise all vertebrates and 2 groups of invertebrates:
Urochordates and Cephalochordates.
4 Key characters of chordates:
- Notochord
- Dorsal, hollow nerve chord
- Pharyngeal slits or cleft
- Muscular, post-anal tail
The __________ is a longitudinal, flexible rod between the digestive tube and nerve chord.
Notochord.
The ________ develops into the Central Nervous System: the brain and the spinal chord.
Nerve Chord.
Functions of the pharyngeal slits (3):
- Suspension-feeding structures in many invertebrate chordates
- gas exchange in vertebrates (except vertebrates with limbs, the tetrapods)
- Develop into parts of the ear, and neck in tetrapods
________ (Urochordata) are more closely related to other chordates than are lancelets.
Tunicates.
________ share some characteristics: a skull, a brain, eyes and other sensory organs.
Craniates.
One feature unique to craniates is the _________, a collection of cells near the dorsal–these give rise to a variety of structures, including some of the bones and cartilage of the skull.
Neural Crest.
_______ were the first vertebrates with mineralized skeletal elements in their mouth and pharynx.
Conodonts.
_______ are vertebrates that have jaws; include: sharks, ray-finned fishes, lobe-finned fishes, amphibians, reptiles, birds and mammals.
Gnathostomes.
In aquatic gnathostomes, the ________, which is sensitive to vibrations is present.
Lateral Line System.
The earliest gnathostomes in the fossil record are an extinct lineage of armored vertebrates called ________.
Placoderms.
Group of jawed vertebrates that radiated during the Silurian and Devonian periods (444 to 359 MYA)?
Acanthodians.
__________ (sharks, rays, relatives) have a skeleton composed primarily of cartilage.
Chondrichthyans.
________: eggs that hatch outside the mother’s body.
Oviparous.
________: The embryo develops within the uterus and is nourished in the egg yolk.
Ovoviviparous.
_______: The embryo develops within the uterus and is nourished through a yolk sac placenta from the mother’s blood.
Viviparous.
Nearly all living _______ have bony endoskeleton; include bony fish and tetrapods.
Osteichthyans.
Most fishes breathe by drawing water over gills protected by an ________.
Operculum.
Fish control their buoyancy with an air sac known as a ___________.
Swim Bladder.
The ______ (Sarcopterygii) have muscular pelvic and pectoral fins.
Lobe-Fins
Tetrapods have specific adaptations (5):
- 4 limbs and feet w/ digits
- Neck, which allows separate movement of the head
- Fusion of the pelvic girdle to the backbone
- The absence of gills
- Ears for detecting airborne sounds
________ are a group of tetrapods whose living members are the reptiles, including birds and mammals.
Amniotes.
Most reptiles are _______, absorbing external heat as the main source of body heat.
Ectothermic.
Birds are _________, capable of keeping the body warm through metabolism.
Endothermic.
Birds descended from the group, _______, whom were bipedal carnivores.
Theropods.
______ are amniotes that have hair and produce milk.
Mammals.
Mammals have (5):
- Mammary glands, which produce milk
- Hair
- A higher metabolic rate, due to endothermy
- A larger brain than other vertebrates of equivalent size
- Differentiated teeth
Mammals evolved from ________.
Synapsids.
________ are a small group of egg-laying mammals consisting of echidnas and the platypus.
Monotremes.
________ include opossums, kangaroos, and koalas.
Marsupials.
The embryo develops within a ________ in the mother’s uterus.
Placenta.
