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Cards In This Set
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Most vertebrates are _______ (type of animal).
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Fish.
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What is a synapomorphic character?
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A trait shared by two or more taxa as well as their last common ancestor, whose ancestor in turn does not possess this trait.
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What is a pleisomorphic character?
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A trait shared by two or more taxa, as well as their last common ancestor, as well as earlier common ancestors.
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What are four characteristics that define chordates?
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Notochord, dorsal hollow nerve cord, segmented muscular tail, and an endostyle.
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What is an endostyle?
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A ciliated, glandular groove in the pharynx.
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What is a tunicate/urochordate?
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A group of sedentary, underwater, saclike filter feeders from the phylum Chordata.
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What is a lancelet/cephalochordate?
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A group of marine, motile chordates whose notochords extend all the way to the head (unique among vertebrates). These species give interesting evolutionary insights into the origins of vertebrates.
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How long ago did the earliest vertebrates appear?
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About 530mya.
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Why are hagfish a unique group?
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This group contains the only animals with crania that also lack vertebral columns.
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What are some primitive characteristics of hagfish (compared to vertebrates)?
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No vertebrae, simple kidneys, several independent hearts, three-chambered heart.
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What does the neural crest typically develop into in vertebrates?
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Cranial bones, complex sensory organs, most of the peripheral nervous system, various glands.
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What are some features of the uniquely complex integument of vertebrates?
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Separate dermal layers (epidermis, dermis, and hypodermis), distribution of exocrine and endocrine glands, presence of sensory receptors. The integument is the largest vertebral organ, comprising 15-20% of body weight. It provides protection as well as feedback from the environment.
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What is the difference between the chemical structure of "hard tissues" in vertebrates versus, say, molluscs? What is the benefit of vertebrate chemical structure?
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Vertebrate hard tissue is made of hydroxyapatite, a calcium phosphate. Mollusc hard tissue is made of brittle calcium carbonate. Hydroxyapatite is preferable for vertebrates as it is more stable under acidosis (and vertebrates have a lower blood pH due to their more active metabolisms).
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What are the six types of hard tissue in vertebrates?
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Cartilage, enameloid, enamel, dentine, cementum, and bone.
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How are enamel, dentin, and cementum arranged in the vertebrate tooth?
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Cementum is used to cover the root of the tooth, dentin is porous and covered by hard enamel in the crown.
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