Term
| 3 advancements/special features of cnidarians |
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Definition
1) radial symmetry and oral-aboral axis
2) their ectoderm and endoderm are the same as higher level metazoans
3) they have a gastrovascular cavity with a mouth opening |
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Term
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Definition
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Term
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Definition
jelly-like layer that lies between two tissue layers
makes up most of the body mass of some Cnidarians like jelly-fish |
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Term
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Definition
| a hydroid that is sessile and have diploid chromosomes |
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Term
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Definition
| a free-swimming, jelly fish with diploid chromosomes |
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Term
| classification for Obelia |
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Definition
Phylum: Cnidaria
Class: Hydrozoa
Order: Hydroida
Genus: Obelia |
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Term
| Does Obelia have only polyp, only medusae or both? |
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Definition
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Term
| Explain the life cycle of obelia |
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Definition
1 - polyp comes from a free-swimming plannula larvae
2 - polyp attaches to a substratum
3 - budding forms a colony which includes feeding hydranths and reproductive gonangia
4 - medusa buds are produced in the gonangia
5 - they break away and become free-swimming medusae (jelly fish)
6 - Medusae are dioecious, so when both sexes are mature medusae discharge gametes into water where fertilization occurs
7 - zygote develops into a plannula larva which attaches itself to the sea floor
8 - repeat |
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Term
| Do medusae reproduce sexually or asexually |
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Definition
medusae sexually produce hydroid colonies
hydroid colonies sexually produce medusae |
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Term
| Are medusae dioecious or monoecious? |
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Definition
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Term
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Definition
| having male and female reproductive organs borne on separate individuals of the same species |
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Term
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Definition
| root-like strucutres in obelia that attach to sea weed |
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Term
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Definition
| the main stem of obelia that has lateral branches |
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Term
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Definition
| found on the lateral branches of Obelia... there are two types: hydranths and gonangia |
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Term
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Definition
| in obelia, they are vase shaped, involved in feeding, and have tentacles at their free-ends |
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Term
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Definition
| in obelia, involved in reproduction, they have an elongated club shape and no tentacles |
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Term
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Definition
| in obelia, the thin, transparent protective layer secreed by the epidermis which covers the entire colony |
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Term
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Definition
in obelia, a hollow tube composed of epidermis, mesoglea, and gastrodermis... and a gastrovascular cavity
hydranths are continuous with the coensarc |
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Term
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Definition
| in obelia, the extension of the perisarc that forms a cup around hydranths |
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Term
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Definition
| in obelia, a modification of the perisarc that is around the blastostyle of the gonangium |
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Term
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Definition
| in obelia, finishes in a mouth and has a circle of tentacles around the base |
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Term
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Definition
| in obelia, they bear nematocysts, in the epidermis of tentacles, clusters of them form swellings |
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Term
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Definition
| in obelia, a hollow continuation of the coensarc in the gonangium |
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Term
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Definition
| in obelia, they are saucer-shaped and arise from the blastostyle by transverse budding, and develop into mature medusae |
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Term
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Definition
| in obelia, this the area where the young medusae escape, an opening at the distal end |
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Term
| Classification of Gonionemus (A hydromeduase) |
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Definition
Phylum: Cnidaria
Class: Hydrozoa
Order: Hydroida
Genus: Gonionemus |
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Term
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Definition
| in gonionemus, the outer/aboral surface (it is convex) |
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Term
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Definition
| the oral/inner surface of gonionemus |
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Term
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Definition
| in the gonionemus, they are around the margin of the bell, have rings of stinging cells (nematocysts) |
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Term
| adhesive pads (in gonionemus) |
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Definition
| sticky pads that the animal sticks to its prey |
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Term
| tentacular bulbs (in gonionemus) |
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Definition
-pigmented structures found at the base of the tentacles that make and store nematocysts
-they help with intracellular digestion
-act as sensory organs |
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Term
| Statocysts (in gonionemus) |
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Definition
between the bases of tentacles, they are the organs of equilibrium
--> sacs containing secretions |
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Term
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Definition
| circular, shelf-like membrane on the oral surface |
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Term
| manubrium (in gonionemus) |
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Definition
| hangs from the center of the subumbrellar cavity |
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Term
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Definition
| at the distal end (bottom) of manubrium, has 4 oral lobes |
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Term
| gastrovascular cavity (in gonionemus) |
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Definition
| includes gullet, stomach, 4 radial canals, 1 ring canal |
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Term
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Definition
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Term
| epidermis (in gonionemus) |
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Definition
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Term
| gastrodermis (in gonionemus) |
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Definition
| lines entire gastrovascular cavity |
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Term
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Definition
| in between the epidermis and the gastrodermis... it is thicker in the medusa than hydroid form |
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Term
| classificatino of Aurelia (true jelly fish) |
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Definition
Phylum: Cnidaria
Class: Scyphozoa
Order: Semaeostomae
Genus: Aurelia |
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Term
| Characteristics of scyzphomedusae |
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Definition
- have tetramerous radial symmetry (parts are symmetrically arranged around and oral-aboral axis in multiples of four)
- have lots of cellular mesoglea
- do NOT have a velum |
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Term
| How many intervals is the aurelia broken into? |
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Definition
| 8 (aka there are 8 marginal lappets) |
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Term
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Definition
sense organs that are in the marginal notches
they have a statocyst and a pit or 2 lined with epithelium |
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Term
| What would happens if rhopalium were removed (in aurelia) |
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Definition
| it would mess up their swimming because they would have much slower contractions or the contractions would stop altogether |
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Term
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Definition
there are 4... they come out of the center of the oral side
- they are tough modifications of the manubrium
-converge towards the center of the mouth |
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Term
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Definition
| the mouth leads to the gullet, and the gullet leads towards the stomach |
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Term
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Definition
extend from the stomach
contain horseshoe shaped gonads
there are 4 of them |
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Term
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Definition
| in the gastrovascular cavity they can impale and hold small things, therefore subduing the prey at the beginning of digestion |
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Term
| subgenital pits (in aurelia) |
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Definition
a round aperture on the oral side of each gastric pouch
- have a respiratory function |
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Term
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Definition
| run from the gastric pouches to the circular canals |
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Term
| circular canals (in aurelia) |
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Definition
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Term
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Definition
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Term
| What are the 4 life stages in the life cycle of aurelia? |
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Definition
plannula larva
scyphistoma
strobila
ephrya larva |
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Term
| Classification of Metridium |
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Definition
Phylum: Cnidaria
Class: Anthozoa
Order: Zoantharia
Genus: Metridium |
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Term
| What are the 3 main regions of Metridium |
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Definition
1) oral disc with tentacles and mouth
2) the cylindric column
3) basal disc |
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Term
| siphonoglyph (in Metridium) |
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Definition
a ciliated groove, it is smooth-surfaced
- may be two of them
-create a current of water into the pharynx
- caused bilateral symmetry |
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Term
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Definition
| a smooth space that separates tentacles from the mouth |
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Term
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Definition
the mouth extends into this
- it extends partway down then opens into a gastrovascular cavity
- it is considered the inner tube |
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Term
| Complete/Primary Mesenteries/Septa (in Metridium) |
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Definition
they divide the gastrovascular cavity into six chambers
they extend from the body wall to the gullet |
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Term
| retractor muscles (in Metridium) |
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Definition
| longitudinal muscles that run from the basal disc to the oral disc |
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Term
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Definition
small oval holes next to the gullet,
used for communication amongst mesenteries |
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Term
| incomplete mesenteries (in Metridium) |
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Definition
extend varying distances from the body wall into the gastrovascular cavity
- they extend from oral to aboral ends
- they are free at their inner edges
- made of double sheets of gastrodermis |
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Term
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Definition
at the free ends of the mesenteries
- bear cniocytes/secrete digestive enzymes |
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Term
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Definition
- delicate threads attached to septal filaments
- have stinging cells
- may be protruded through the mouth or body pores in defense |
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Term
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Definition
thickened bands on the mesenteries
found between septal filaments and messentry |
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Term
| Classification of Planarian (free-living flatworm) |
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Definition
Phylum: Platyhelminthes
Class: Turbellaria
Order: Tricladia
Genus: Dugesia |
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Term
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Definition
| it is triangular in shape |
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Term
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Definition
- ear-like structures
- have many sensory cells
- are tactile/olfactory in nature, not auditory |
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Term
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Definition
- organelles in the ciliated epidermis
- secrete a path of mucus that helps planarians propel themselves |
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Term
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Definition
| increase the capacity of the pharynx/digestive surface |
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Term
| are planarians dioecious or monoecious? |
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Definition
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Term
| what are protonephridia in planarians? |
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Definition
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Term
| In planarians, what is the function of the protonephridial system? |
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Definition
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