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43 Cards in this Set
- Front
- Back
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Describe the members of phylum onychophora |
elongate, bilaterally symmetrical eucoelomate protostomes that moult a chitinous cuticle |
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What are nematodes referred to as? |
pseudocoelomate |
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What is a pseudocoel? |
body cavity derived from the blastocoel and lined only on the outer surface by tissue of mesodermal origin. It is fluid filled |
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What organ systems are suspended within the pseudocoel of nematodes? |
digestive, reproductive and excretory |
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Describe the external cuticle of nematodes? (round worms) |
a non living collagen layer. Nematodes moult this layer as they grow |
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The larger protostome group that consists of nematodes, arthropods and onychophorans |
Ecdysozoa |
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What is eutely |
a constant number of cells within a species. (Nematodes have this.) |
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important biological phenomena of nematodes |
cryptobiosis(withstanding extreme conditions) and parthogenesis(developent of an unfertilized egg into an adult organism) |
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Covered organism/ genus' in phylum nematoda |
Turbatrix and Ascaris |
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Covered genus' in phylum Onychophora |
Peripatus |
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The head of peripatus bears what? |
a pair of antennae |
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What does the mouth of peripatus bear? |
lateral unjointed oral papillae and a pair of mandibles used in food preparation. |
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Both the mandibles and oral pappillae are modified from what? (peripatus) |
trunk appendages |
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Describe the trunk appendages of peripatus. |
lacking joints and bearing claws |
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The cuticle of peripatus is made of what? |
chitin but is thin and flexible |
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What is the body of peripatus covered with? |
Tubercles |
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The muscles of the body wall of peripatus are arranged as... |
circular and longitudinal layers. (like annelids) |
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What is the coelem reduced to in peripatus? |
cavities |
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Reproductive representations of peripatus? |
all dioecious and different species may be oviparous, ovoviviparous or viviparous |
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What kind of circulatory system do peripatus have? |
open circulatory system |
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how does peripatus respire? |
tracheae |
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What kind of heart does the peripatus have? |
a perforated heart. |
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Nematodes have these biological conditions |
cryptobiotic |
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many species of nematodes have a regular period of diapause which is... |
a dormant period of time |
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Describe a typical nematode |
unsegmented and bilateral symmetry |
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Where is pig roundworm, Ascaris sp. found? |
it is an animal parasite sometimes found in humans |
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In ascaris, is the female or male larger? |
The female |
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Male ascaris have a curved tail usually with what and what is the funtion? |
copulatory spicules to hold the females vulva open during copulation. |
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how many lips surround the mouth of ascaris? |
3 |
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Where is the anus located in ascaris? |
posterior and ventral |
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The body cavity of ascaris is lined with what? |
longitudinal muscle cells |
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Each muscle cell of ascaris has what? |
a process passing to the nerve chords at the dorsal and ventral midline. (unique to nematodes, usually the opposite) |
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What nerve cords does an ascaris have? |
dorsal, ventral and two lateral |
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What acts as a muscular pump during feeding in ascaris? |
pharynx |
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what is the intestine of ascaris lined with? |
ciliated columnar epithelium |
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What does the excretory ducts pass through in ascaris? |
the lateral nerve cords. |
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How can you determine the difference between the ovary and oviduct in the ascaris cross section? |
the ovary is smaller and more densely stained. |
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do sperm have flagella in nematodes? |
no |
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How can you tell the difference between the testis and vas deferens in the ascaris cross section? |
The testis are smaller and more deeply stained. |
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What creates the hydrostatic skeleton in nematodes/ascaris? |
the pseudocoelomic fluid being incompressible, and helical arranged fibers in the cuticle , all acting as an antagonist to the longitudinal muscles. |
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what is the vulva? (ascaris) |
a separate opening for the reproductive tract which opens ventrally, midbody. |
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the intestinal and reproductive tracts of ascaris males converge posteriorly to form a common duct... |
cloaca |
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describe nematode movement? |
graceful sinusoidal waves |
