Study Guides (238,406)
United States (119,772)
BIOL 1202 (108)
All (83)

Exam 4 Notes (got 93% on the test)

33 Pages
Unlock Document

Louisiana State University
Biological Sciences
BIOL 1202

Exam 4Chapter 33InvertebratesoMost Recent Hypothesis about Animal PhylogenyFigure 3222MetazoaPorifera SpongesHave no true tissues or organsEumetazoa True multicellular animalsContains Diploblastic 2 tissue layersBilateria Triploblastic 3 tissue layersConcept 331Sponges are basal animals that lack true tissuesoPorifera Phyla CalcareaSiliceaLive in both fresh and marine watersLack true tissues and organsAsymmetrical bodyoMostly live in Marine WatersoOrganized only at the cellular levelNo true tissuesMore loosely interconnected with one anotherSpongesoSponges are suspension feedersFilter water passing through their bodiesoFigure 334oCovered with a layer of epidermal cellsThey have openings called Porocytes donutshapedoThe interior is called the spongocoeloThe matrix is called the mesohyloChoanocytes have flagella that move to push water out through the osculumThey trap food in their collar and move that food to other cells such as amoebocytesoClicker QuestionWater movement through a sponge would follow what pathPorespongocoelosculumBlastoporegastrovascular cavityprotostomeChoanocytemesohylspongocoelPorechoanocytemesohylConcept 332 Cnidarians are an ancient phylum of eumetazoansCnidariansoA wide range of sessile and floating forms including jellyfish corals and hydrasoSimple diploblastic radial body plan cylindrical body planBody plan is a sac with a central gastrovascular cavityGastrovascular cavity is where the food goes in and is absorbedSingle opening serves as both mouth and anusMesoglea layer between epidermis and endodermis gastrodermisJellylike matrix not a true tissue layerGives jellyfish their nameCnidarian Body PlansoPolyp form is generally sessileIt attaches itself to the base of a body stalksubstrate and extends its tentacles into the surrounding wateroMedusa form moves freely in water by passive drifting and contractions of the bellLooks like the polyp except upside downoFigure 335Defining Feature of CnidariansoCnidocytesUnique cells that function in defense and the capture of preyGenerally found in the epidermal layer of tentaclesoStimulus causes the cell to evert releasing threadoSome cnidocytes sting others just entangle preyoFigure 336oNematocystsContain a barb on jellyfish that can attackCnidarian DiversityoFigure 337 Table 331oScyphozoaHave a nice round bell shape Medusa stageoCubozoaTheir bell is a boxlike shapeMedusa stageThey have a toxin in their nematocystsoAnthozoaPolyps Nemos houseClicker QuestionHow many planes through the central axis will divide an organism with radial symmetry into roughly equal halveso1o4o10oManyIt is infinitely manyClicker QuestionWhich of the following animals is responsible for more lethal attacks on humans each yearoSharksoKiller WhalesoSnakesoCubozoansJellyfishConcept 333Lophotrochozoans a clade identified by molecular data have the widest range of animal body formsoFigure 332oBilateria TripoblasticOrganisms that are bilaterally symmetricalShow cephalization and 3 tissue layersLophotropozoansoFlatwormsPhylum platyheminthesPlatyhemin means flat wormThey have a gastrovascular cavityTriploblastic development but acoelomateHas an outer epidermal layerHas an inner endoderm that lines the digestive cavityHas a mesoderm sandwiched between those twoThis is why it is triploblasticAcoelomate because there is solid tissue between the ectoderm and the endodermoFigure 332Classes of PlatyheminthesoClass TurbellariaHave Lightsensitive eyespotsCentralized nerve net with anterior gangliaGastrovascular cavity with a twoway pharynxFlatwormMost common one is planarianoFigure 339 and 3310oClass Trematoda
More Less

Related notes for BIOL 1202

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.