Term
| Among the chordates are the fish, amphibians, reptiles, birds and mammals. Name the two other more basal groups of chordates |
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Definition
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Term
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Definition
| Rod-like, semi-rigid, enclosed in sheath |
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Term
| What is the purpose of the notochord? |
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Definition
| To stiffen the body, providing skeletal scaffolding for attachment of muscles |
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Term
| The earliest chordates and vertebrates in the fossil record are found in what geological time period? |
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Definition
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Term
| What occured in the Ordovician, some 505-438 mya? |
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Definition
| The beginning of the fish radiation |
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Term
| What occured in the Silurian, 438-408 mya? |
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Definition
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Term
| What occured in the Devonian, 408-360 mya? |
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Definition
| Amphibians first appear, also 'Age of the Fishes' |
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Term
| What occured in the Carboniferous, 360-286 mya? |
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Definition
| First reptiles, also 'Age of the Amphibian' |
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Term
| What occured in the Permian, 286-245 mya? |
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Definition
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Term
Which geological period envelopes from the Cambrian to the Permian?
A: Paleozoic
B: Cenozoic
C: Mesozoic |
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Definition
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Term
| What features do chordates share with invertebrates? |
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Definition
Bilateral symmetry
Anterio-posterior axis
Coelom
Tube-within-a-tube body plan
Metamerism
Cephalisation |
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Term
| What are the main features of a chordate? (at some point in its life) |
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Definition
Dorsal, tubular nerve cord
Notochord
Pharyngeal slits
Endostyle
Postanal tail |
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Term
| What replaces the notochord in protochordates? |
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Definition
| Nothing, it persists throughout life. It is replaced by vertebrae in the vertebrates |
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Term
| Remnants of the notochord may persist between/within vertebrae. True or false? |
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Definition
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Term
| The posterior end of the nerve cord enlarges to form the brain, true or false? |
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Definition
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Term
| What is the purpose of pharyngeal slits? |
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Definition
| Filter feeding in protochordates, led to evolution of gills in fishes (from capillary network) |
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Term
| What is the derivative of the endostyle, found in all chordates |
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Definition
| The thyroid gland, which secretes iodinated compounds |
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Term
| What is the function of the chordate postanal tail? |
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Definition
| Provided motility for larval tunicates and Amphioxus to swim. Efficiency increased in fishes but became smaller or vestigial in later lineages |
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Term
| Name the three sub-phyla within chordata and their distinguishing features |
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Definition
Urochordata (Tunicata): Marine, most adults sessile, surrounded by tough test, adults lose many of the key chordate characteristics
Cephalochordata (Lancelets): Slender, laterally flattened, translucent, 5-7cm, marine suspension feeders, retain chordate body plan as adults, segmented body, endostyle secretes mucus used in feeding, referred to as amphioxous
Craniata (Vertebrates): Cephalisation, neural crest, ectodermal placodes, active predation, tripartite brain, paired special sense organs, muscoskeletal and respiratory modifications, muscular gut, accessory digestive glands (liver and pancreas) |
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Term
| Name the three classes of Tunicates and their features |
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Definition
Ascidiacea (sea squirts - tunicates): Incurrent and excurrent siphons, can anchor to substrate, colonial or solitary
Appendicularia (larvaceans): hollow from mucus surrounds animal
Thaliacea (salps): pelagic, lemon shaped, transparent |
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Term
| The plate like thickenings that appear on either side of the neural tube in vertebrates are called ____ |
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Definition
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Term
| What is an advantage of an endoskeleton? |
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Definition
| Permits almost unlimited body size with much greater economy of building materials, provide more area for attachment of segmented muscles |
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