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80 Cards in this Set

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What are some general chatacteristics shared by the eumetazoan phyla, Chidaria and Ctenophora? 4 of them.
-radial symmetry
-have tissues but organs are poorly developed if present
-body wall is composed of an outer 'epidermis' and an inner 'gastrodermis' seperated by a mesoglea.
-basically an 'ectoderm' and an 'endoderm', therefore they are considered 'diploblastic'
What kind of animals does the phylum Cnidaria include? 4 of them.
-jelly fish
-sea anenomes
What are some characteristics shared by all cnidarians? 6 of them.
-radially symmetrical
-have a gastrovascular cavity/coelenteron
-have tentacles around the mouth-anus
-body wall has 3 recognizable layers:
1)Epidermis 2)Mesoglea 3)Gastrodermis
-typically polymorphic
-have 'cnidoblast'
What is polymorphic?
-means that individuals of a species exhibit different forms at different stages of the life cycle

**2 most distinctive cnidarian forms are the MEDUSA and POLYP**
What are cnidoblasts?
-stinging cells on all cnidarian
-contains a nematocyst
-nematocysts are a cyst-like capsule containing an inverted, hollow, coiled thread.
***nematocysts are what is discharged, not the cnidoblast***
List and describe the 3 types of nematocysts.
1)Penetrant:-has prominent basal spines on the tube(nema)
-basal spines rotate rapidly as nematocyst is discharged. discharges with shit loads of force. bust up arthropods!!
-spines retract and the long thin part of the nema enters the hole, releasing an anesthetic fluid into the prey.
-causes pain, numbness, paralysis, etc.

2)Glutenant:-has a sticky tube which attaches to prey organism and may even wrap around finer structures

3)Volvent:-isn't sticky but has small spinelike projections that allow it to cling to and coil around prey organisms
What are the 3 classes found withing the phylum Cnidaria?


What are the characteristics to Gonionemus? phylum, anatomy, etc.
-belongs to the class hydrozoa
-medusa has gonads therefore is considered to be the adult stage of the life cycle
-bowl shaped-convex/outside surface is exumbrellar/aboral. Concave/inside surface is subumbullar/oral
-has a velum
-sexually dimorphic
-radial symmetry (tetramerous)
What is a 'velum'?
-a shelflike membrane around the margin of the medusa
-a broad cirular band of muscle
-rhythmical contractile movement of velum moves the gonionemus medusa (jet propulsion)

**therefore, velum is important for movement**
What is the manubrium?
-the tubular structure at the centre of the subumbrellar cavity
-opening at the distal end is the mouth/anus
-inside the manubrium is the 'gullet' which leads to a four sided stomach
What is dioecius?
-a species showing separate seces
What makes up the digestive/gastrovascular system of gonionemus?
-radial canals
-ring canals
What are some features of the gonionemus tentacle?
-base has a brownish 'tentacular bulb'. Bulbs make and store cnidoblasts
-tentacles have spiral welts on them, 'spiral welts' are full of cnidoblasts
-has adhesive pads approx 2/3 down the tentacle away from the base
What are lithocysts?
-an organ of equilibrium found in gonionemus and others.
-located between tentacular bulbs
-look like a small stone surrounded by a halo
-stone in the lithocyst touches small sensory hairs, therefore alerting the gonionemus about it's whereabouts
How does Gonionemus feed?
-swims toward the surgace with mouth down
-once near surface, it flips(mouth up) and sinks slowly with all tentacles extended and trailing to catch prey
-when it reaches the bottom, it attaches with it's adhesive pad with mouth up and catches food
How do Gonionemus reproduce?
-mature medusae produce gametes in gonads
-male spermatazoa are released from the gonads into the sea
-female eggs are released into the sea
**therefore fertilization is EXTERNAL!**
-resulting zygote is a free swimming 'planula larvae'
-swims for a bit but eventually settles and metamorphoses into another larval form called 'POLYPLOID' or 'HYDROID'. these guys look like bowling pins with 4 tentacles
-the mature polyp is called 'ACTINULA'
-actinula can bud 'gonophores' off of it's side which developes into medusae -or it make for actinulae by budding off 'frustules' which mature to be actinula
What is Actinula?
-a mature gonionemus polyp
What are gonophores?
-budding that comes off the sides of actinula
-mature into medusae
What are Frustules?
-budding that comes off of actinula
-matures to become actinula
We know that gonionemus spends the majority of it's life cycle in the medusae stage. In what stage does Obelia spend the majority of it's life?
-spends majority of it's life in the polypoid stage.
What is the 'hydrorhiza'?
-a rootlike organism that anchors the obelia polyp colony to seaweed
What is the hydrocaulus?
-hydrocaulus is the main stem of the obelia colony
What is the gastrozooid?
-AKA nutritive hydranth
-an obelia polyp whose function is to feed the colony
-sits within the hydrotheca
-has tentacles and an elevated hypostome
What is a gonozoid?
-an obelia polyp responsible for making medusae
-consists of a blastostyle, which bears the gonophores that will mature into medusae
-sits within the gonotheca
**The gonozooid and the gonotheca are referred to as the gonangium**
What is the coenosarc?
-the inner red staining protoplasmic core of the hydrocaulus.
-a hollow tube composed of 2 layers of cells, an epidermis and a gastrodermis with a thin layer of mesoglea between them
What is the perisarc?
-a protective covering which surrounds the coenosarc
-secreted by the epidermis
What is the blastostyle?
-the stalk like organism inside the gonotheca which bears the gonophores (mature into medusae)
What is the gonotheca?
-specialized perisarc which surrounds the blastostyle of the gonozooid
What's the gonangiopore?
-an opening at the tip of the gonetheca
-medusae swim out through here
Tell me a little something about the life cycle of obelia.
-medusa is the adult stage since it bears the reproductive organs
-medusa releases gametes into the sea, fertilization is external
-zygotes develope into small, ciliated, freeswimming planula larvae
-planula larvae settle and metamorphs into a polyp colony.

**obelia exhibits alternation of generation because it has both an asexual and a sexual generation in its life cycle**
What is the main purpose of polymorphism?
-species that undergo polymorphism change forms as a way to overcome lack of organs
-has forms for eating, defense, mating, etc.
What is a dactylozooid?
-a defensive polyp of the hydractinia
-hydractinia live on the surface of hermit crabs
What are the 3 types of polyps that have from the portuguese man of war?

What genus do portuguese man of war belong to?
-gastro/gono/dactlyozooids hang off of it

-belongs to the genus physalia
How does hydra attach itself to substrate?
-attaches with basal disc
What are some characteristics of hydra?
-not polymorphic
-radial symmetry
-hydrostatic skeleton
-no real nervous system, rather, it has a nerve net
-nerve cells of hydra are star shaped
What are epitheliomuscle cells?
-most numerous cells in the nucleus
-medium sized cells with large, dark staining nuclei
-cuboidal shape
What are interstitial/totipotent cells?
-these cells are embryonic, nonspecialized cells that have the potential to develp into any of the cells of the epidermis
What cells are present in the hydras gastrodermis?
-Nutritive Muscle Cells: intertwined, elongated cells; most of these cells have flagella which help move nutrients

-Gland Cells: scattered among the nutritive muscle cells; secretion granules that provide enzymes for extracellular digestion
How do the muscles in a hydra allow it to move?
-if longitudinal muscles contract while circular muscles elongate, hydra contracts
-if longitudinal muscles relax while circular muscles contract, hydra elongates
**you can imagine how hydra does side to side movement**
-hydras change position by somersaulting
When do hydras reproduce asexually?
-during the warm summer months
-reproduce by budding
When do hydras reproduce sexually?
-during the fall
-male releases sperm into the water, where they then look for eggs on the sides of female hydras
What is the scalloped phase of a female hydra?
-when an amoeboid cell in the ovary becomes dominant and eats all of the other cells, becoming one large egg
What is a stereogastrula?
-a gastrula that is formed by the inwandering of cells rather than invagination

**hydras have stereogastrulas**
What are 6 major characteristics to the class Hydrozoa?
1)they are truly diloblastic, mesoglea is noncellular

2)They are typically polymorphic with medusoid, hydroid and planular stages

3)they are radially symmetrical

4)they occur as individuals or in colonies

5)their gonads are derived from ectoderm, gametes being released directly to the outside of the body

6)they lack cnidoblasts in the gastrodermis
What class does aurelia belong to?
-belongs to the class scyphozoa
What is rhopalium?
-AKA tentaculocyst
-found on aurelia, 8 equally spaced notches
-located between 2 lobelike 'Lappets'
-rhopalium is a sensory organ consisting of a 'pigmented eye', a 'statocyst' and 2 'sensory pits'

**Statocyst is a balance organ, controlling muscle contraction.
Sensory pits contain chemoreceptors**
Go over the life cycle of Aurelia. Start with the developement of planula.
1)mature sperm are discharged into the gastric pouches and released out of the mouth. Sperm are swept into the gastric pouches of the females where the eggs are fertilized.

2)zygotes escape through the mouths of the females and are caught in the folds of the oral arms where they undergo development. (ie:coelogastrulation). Stays there until planula larvae is developed

3)ciliated planula eventually detaches from mother, swims, settles and metamorphs into a small polyp called 'SCYPHISTOMA'

4)Scyphistoma undergoes strobilation, producing immature medusae called 'EPHYRA' by a process of sequential budding off distally, one after another and becoming free swimming ephyrae

5)Ephyra will mature into a mature medusa in about 2.5months
List 8 important characteristics of the Class Scyphozoa.
1)They are radially symmetrical
2)The gastrodermis has cnidoblasts
3)The gonads are gastrodermal in origin (shaped like horseshoes)
4)The medusa is the dominant stage in the life cycle
5)The medusae have wandering amoeboid cells in their mesoglea
6)They have sensory organs on the rim called rhopalia
7)Most of them lack a velum
8)Don't swim too much
9)Suspension feeders
10)They are relatively large therefor their radial canals branches alot
What are some characteristics to the class Anthazoa?
-do not have a medusoid stage in their life cycle... but do have a planula larva
-considered triploblastic because of thick mesoglea layer
-polyps can show radial or bilateral symmetry, depends on number of siphonoglyphs
What is the function of the pedal disc on Metridium?
-muscular and slimy
-well adapted for slow gliding over rocks or for tight attachment to substratum
What is the stomodeum?
-found immediately following the mouth/anus
-formed by an invagination of ectoderm during embryonic life
What are siphonoglyphs?
-ciliated grooves running down the length of the stomodeum
-determines symmetry
-contains flagellated cells which propel oxygen bearing water inward
What is septa and where is it found?
-members of class anthazoa have septa
-primary septa seperates the coelenteron
-secondary and tertiary septa don't reach the gut wall
-serves to increase surface area in the gut
-longitudinal muscles are found in septa
-gonads are found in septa
-nemotcyst bearing thread like structure called acontium is found at the base of septa
How does metridium reproduce?
-can reproduce sexual and asexually
-reproduces asexually in 3 ways
1)Pedal Laceration: occurs when part of the pedal disc is left behind when the animal moves away, this remainder can grow into a new anemone
2)Pedal disc can put out a lobe that detaches and produces a new anemone
3)The entire polyp can divide by longitudinal fission, producing 2 polyps
Sexual Reproduction:
Zygotes develop into freeswimming ciliated planula larvae, they metamorph into young polyps and settle on the ocean bottom
What are some features of Astrangia?
-corals belonging to the class Anthozoa
-forms small colonies of 2 to 3 dozen individual polyps
stoney coral with a hard calcareous skeleton
-polyps are characerized by their tentacles
-polyps lack a siphonoglyph
What is Theca?
-the cups in the skeleton of astrangia which holds the polyps
-has hard ridges that push up into the fleshy septa of the polyp called 'SCLEROSEPTA'
-there are 12 sclerosepta per theca, meeting up in the middle forming a pillar called the 'COLUMELLA'
What is Zooxanthellae?
-a symbiotic algae living in most coral
-nitrogen and phophorus are cycled between coral and algae
-symbiosis also allows the deposition of the coral skeleton
What are the characteristics of the class Alcyonaria?
-soft corals
-has pinnate tentacles (ie:presence of lateral branches coming off the central axis of the tentacle like the side branches coming off the main shaft of a bird feather)
What are 6 characteristics of the Class Anthazoa?
1)There is no medusoid stage
2)they have a well developed stomodeum
3)the gastrovascular cavity is divided by mesenteries
4)the gastrodermis contains nematocysts
5)the gonads develop in the gastrodermis
6)the mesoglea contains cells and fibers
What phylum do 'pleaurobrachia' belong to?
-belongs to the phylum ctenophora
-swims about in surface waters of warm oceans
What is costae?
-8 rows of little combs that run longitudinally along pleurobrachia

-combs or 'CTENE' consists of a row of long cilia fused together
What is the 'aboral sense organ'?
-a balancing and steering mechanism on pleurobrachia
-in its center is a pit containing a 'STATOCYST' which acts like a lithocyst
How do Ctenophores move?
-move by beating their CTENES
-like having a team of rowers
-movement can be forward or backwards
-unique to Ctenophores
-arranged radially along the axis of the lateral filaments of the tentacle
-discharges a sticky secretion from a crescent of secretory granules when touched
-used to capture food
-the free swimming larva of pleurobrachia
Draw and label a gonionemus medusa.
What class does gonionemus belong to?
*Belongs to Class Hydrozoa

Did you get:
-liplike lobe
-oral surface
-aboral surface
-circular ring canal
-radial canal
Draw and label a actinula larva.
Whose polyp is the actinula larva?
*Actinula larva is a polyp of Gonionemus

-show frustules and/or gonophores
Draw and label an obelia medusa.
What class does obelia belong to?
*Belongs to class Hydrozoa

Did you get:
-vistigial velum
-radial canal
Draw and label an obelia polyp colony.
What class does obelia belong to?
*Belongs to class Hydrozoa

Did you get:
-coenosarc(epi and gastrodermis)
-mouth anus
Draw and label physalia.
What class does physalia belong to?
*Belongs to class Hydrozoa

Did you get:
Draw and label a hydractinia colony.
Did you remember:
-grows on shelled animals
Draw and label a hydra. Whole, cross section and cell diagrams
What class does hydra belong to?
*Belongs to the class Hydrozoa

Did you get:
-spiral welts
-basal disc
-cnidoblast in epidermal cells
-secretory granules in gastrodermal gland cells
-mother sperm
-mature sperm
-interstitial cell
Draw and label a hydrozoan tentacle.
Did you get:
-spiral welt
-tentacle bulb
-adhesive bulb
Draw and label an aurelia medusa.
What class does aurelia belong to?
*Belongs to class Scyphozoa

Did you get:
-oral arms
-gonad(horseshoe shaped)
-gastric filaments
-radial canals (lots of branching)
-ring canal
-gastric pouch
Draw and label a Scyphistoma larva
Did you remember:
-larva of aurelia
-mouth basal disc
Draw and label the process of strobilation.
Did you remember:
-process for reproducing aurelia
-mature ephyrae on the distal end
Draw and label an ephyra larva.
Did you remember:
-ephyra is a larva of aurelia
-gastric filament
-canal system
Draw and label metridium.
What class does metridium belong to?
*Belongs to class anthozoa

Did you get:
-septal filament
-longtitudinal muscle
-1, 2, 3 septa
Draw and label astrangia.
What class does astrangia belong to?
*Belongs to the class Anthozoa

Did you get:
-maybe draw a polyp for the hell of it
Draw and label pleurobrachia.
What phylum does pleurobrachia belong to?
*Belongs to the Phylum Ctenephora

Did you get:
-aboral region with
--->polar field
--->cilated groove
--->blind anal canal
-opening of tentacle sheath
-short filament
-ciliated groove
-aboral canal
-gastric cavity
-glandular wall of stomadeum
-Colloblast with: straight filament, coiled filament, secretory granule