Zoology Ch. 7, 8, & 9 Study Guide

What are the general characteristics of Anthozoa

()no medusa stage ()can be colonial or solitary ()symbionts to algae ()gastrovascular cavity divided into chambers by septa or mesentaires, leads to pharynx, ()external radial symmetric

Give the general characteristics of the Phylum Ctenophora.

()planktonic ()medusa-like body ()comb rows as locomotion ()biradial symmetry ()no polymorphism ()does not form colonies.

Nemertea are what type of worms?

"Ribbon worms", they have an eject able probiscis

What is the common name for worms belonging to the Phylum Acanthocephala? What is the most characteristic feature of this phylum?

"Spiny headed worms"- thorn head

Be able to identify the following structures associated with rotifers; corona, mastax, and toes.

()Corona(crown)- cilia that draw a vortex of water into the mouth ()Mastax- mouth opening, chewing pharynx ()Toes- two protruding flaps often found on the end of the foot

What is the meaning of the term "rotifera"? List the general characteristics of the Phylum Rotifera.

()Digestion- via corona, trophi to mastax ()Excretory ()Nervous system ()Reproduction- parthogenesis, no fertilization ()Eutely

What is meant by "Gastrotricha"? What are the general characteristics of this phylum? What are solenocytes and what do they replace in the gastrotrichs?

()Hairy belly or stomach. ()pseudocoel reduced and fillied with asmoebocytes ()freshwater and marine ()many are benthic ()either on the substrate or vegetation ()solenocytes replaces flame cells

What are the general characteristics of the Xenoturbellids?

()Lack a true gut ()Mouth opens directly to digestive cavity which is lines by unciliated cells ()No brain present.

List the general characteristics of the Class Cestoda.

()Most specialized class. ()Long tape-like bodies of repeating proglottids. ()No true segmentation. ()No digestive system, absorbs things. ()No cilia in adults. ()1,000 species. ()Syncytial tegument- Outer skin, protection, and absorption

The Phylum Brachiopoda resembles what other group of animals? How are they different from this "other" group of animals?

()Often called lamp shells, shells like some mollusk (different in that the shells not equal in size) ()30,300 species but only 300 living ()Lophophore in anterior coelom of shell

Describe the general features of the Phylum Entoprocta. By what means do the entoprocts acquire food?

()all sessile ()can be colonial or free ()do not look like any other pseudocoelomate ()all marine except for one genus ( Urnatella) which is freshwater and live on benthic insects ()are filter feeders

What are the general characteristics of the Class Cubozoa? Which of the cubozoan jellyfish is considered to be of extreme importance and why?

()cubed and not cute ()most are dimorphic ()only found in warm waters ()base of each tentacle is flattened ()have multiple eyes chironex fleckeri (sea wasp) they are important because their venom can be used in medical research to find a cure for heart problems like cancer.

What are the most general characteristic of the animals in the Clade Polyzoa? Which phyla belong to the Clade Polyzoa?

()have a u-shaped gut ()many are colonial ()may have tentacles The phyla are cycliophora, entoprocta, and ectoprocta

What are the general characteristics of the Phylum Acanthocephala?

()retractable proboscis with recurved spines- ejects out of the mouth, for attachment ()endoparasites of vertebrates, 1100 species ()most of the damage caused by this parasite occurs when they attach to the intestine wall ()dioecious with internal fertilization ()the intermediate host is usually an insect or crustacean ()absorbs nutrients through the syncytial tegument ()no circulatory, respiratory, or digestive systems

What are the general characteristics of the Phylum Acoelomorpha?

()small ()many flatworm characteristics ()lack a digestive cavity or pharynx ()two-tailed sperm, contain eggs (monoecious) ()most are symbiotic

What is a mastix? And what is it used for?

A chewing pharynx. Used for grinding of food

What is eutely?

A fixed number of cells, don't produce cells after they reach sexual maturity. They repair itself by enlargement

What is the difference between an acoelomate and pseudocoelomate?

Acoelomate: Without a body cavity Pseudocoelomate: False body cavity, lack peritoneal lining

Explain what is meant by "pseudocoel". What are the advantages of the pseudocoel?

Advantages: greater freedom of movement, space for development and differentiation of organ systems, storage area for waste, hydrostatic skeleton

What is the function of ocelli? Why is this important to planaria? Where are most tactile cells and chemoreceptors located?

Also known as eyespots, they detect light intensity. Let the organism know how deep they are. Acting as photorecptors, using them to move away from light sources.

Acoelomates have what type of symmetry? What morphological development is often connected with this type of symmetry?

Bilateral symmetry Cephalization

Phylum Ctenophora is unique because of what colorful feature?

Bioluminescence (found in digestive system) and comb rows (colorful because it reflects light, located on outside)

Which organism causes "swimmers itch"?

Cercarial dermatitis, caused by an allergic reaction to these parasites that infect some birds and mammals. Released from infected snails into fresh and salt water.

Trochophore like larva have two bands of what along the exterior?

Cilia

What is the main difference between the two classes found in the Phylum Brachiopoda?

Class Articulata- Hinge holds shell together Class Inarticulata- Muscles hold shell together

What does the term "monogenea" mean? Where do you find most monogeneans? What is the most characteristic feature of the Class Monogenea?

Class Monogenea, "one development", include monogenetic flukes. Direct development, no intermediate host. Are ectoparasites, very selective on what part of the host they will attach (example: eye of a hippopotamus). Have a opisthaptor, which is their organ used for attachment. Tremendous reproductive abilities.

Which classes are mainly parasitic? Which of these classes mainly contain the ectoparasites?

Class Monogenea, Class Trematoda, and Class Cestoda Ectoparasites: Monogenea

Explain the difference between the two different classes found in the phylum Ctenophora.

Class Nuda- no tentacles Class Tentaculata- two tentacles

The term "flatworms" include both free-living and parasitic forms, but the free-living forms are restricted to which class?

Class Turbellaria

Explain the relationship between a cnidocyte and a nematocyst.

Cnidocyte is the cell itself that holds the nematocyst and other parts to help in its function. The nematocyst capsule is what holds the stinging capability and is ejected (not retractable).

What is the most characteristic feature of the cnidarians?

Cnidocytes, when triggered these cells shoot out a discharge thread which can entangle or poisen its victim. Triggered by touch or chemically.

Briefly describe the structure of a medusa.

Commonly called a jellyfish, usually has the shape of a bell or an umbrella, with tentacles hanging downward at the margin. The tubelike manubrium hangs from the centre of the bell, connecting the mouth at the lower end of the manubrium to the coelenteron within the bell.

How are reefs constructed?

Coral reefs are built by coral polyps as they secrete layers of calcium carbonate beneath their bodies

What class of jellyfish have multiple eyes and are not cute?

Cubazoa, they have multiple active eyes that are importance because they help them forage and avoid predators.

Benthic means?

Deep water

Explain the difference between dimorphism and polymorphism. (Hint, some of these classes we discussed can have specialized roles of feeding, reproduction, defense). Which of these is more common in the Cnidarians?

Dimorphism: has two stages in life cycle; polyp- mostly sessile and medusa- free-flowing. Polymorphism: has many stages in life cycle; Larval stage- planula, fixed poly- scyphistoma, and metamorphosis- strobilia or budding polyp. Most common is dimorphism

Monogenea are what type of parasites?

Ectoparisites, located on specialized areas of animal. For example on the gills of fish (reasons: tons of blood flow and hard to get them off)

Are Bryozoans ectoprocta or endoprocta?

Ectoprocta

What are the major characteristics of the radiate animals?

Either are radial (Cnidaria) or biradial (Ctenophora).

List the general characteristics of the Class Trematoda.

Endoparasites of mulloscs and vertebrates (found in blood, liver, lungs, intestine). Digenetic flukes, structurally very similar to tubellarians, syncytial tegument (lack cilia, food uptake, and protection).

What are the different types of polyps on Physalia?

Gastrozooids: digestion Gonozooids: reproduction Pneumatophore: gas-filled polyp Dactylozooids: locates and catches prey

Which phylum is often called the "jawed worms"? What are the general characteristics of this Phylum?

Gnathostomulida ()shaped like bowling pin ()one cilia per cell except for near head ()share some features with the turbellarians but have lateral jaws.

Define "protandric".

Having male sexual organs while young, and female organs later in life.

What are the main parts of a Hydroid colony, and what are their functions?

Hydrorhiza-roots, Hydrocauli- main stem, Perisarc- exoskeleton bendable at sections, Hydranth- feeding, Gonangium- budding

Blood flukes belong to what genus? And what disease?

In Schistosoma. Causes Swimmer's Itch- caused by them bearing into the skin. Snails are carriers. Disease is called schistosomasis

What are the advantages pseudocoelomate body plan?

Increased movement, more space for organelles, storage for waste, and hydrostatic skeleton

What is meant by an indirect life cycle? Direct life cycle?

Indirect life cycle: Direct life cycle:

What is unique about Turritopsis dohrnii lifecycle? Explain how this works.

It turns out that once the adult form of the 4.5 mm-wide species Turritopsis dohrnii have reproduced, they don't "die" but transform themselves back into their juvenile polyp state. Their tentacles retract, their bodies shrink, and they sink to the ocean floor and start the cycle all over again.

Where is the nerve net located in the cnidarians? How is this nerve net or plexus similar and different from our nerve network?

Located at the base of ectoderm and endoderm. It has bidirectional neurotransmitters, has neuromuscular system, lack myelin, and no central nervous system. also, CNS meet up in one single place (brain) whereas the nerve net has no single meeting place.each cnidarian has its own nerve net.

Where are cnidocytes normally located in the cnidarian?

Located on the tentacles

If you wanted to attempt to find an excuse to skip a test, which fluke would you most likely to have the highest success with (within the US). What did you eat the night before that test? Table 8.1)

Lung fluke

Which of the dimorphic forms is considered a complete and typical cnidarian?

Medusa stage

In what type of habitat do you find most cnidarians?

Most are marine, some freshwater and not terrestrial forms - mostly tropical.

Is the nerve net the same as the central nervous system? Explain.

No it has no central nervous system, has a neuromuscular system.

Operculum?

Opening of nematocyte

Statocyst are used for what?

Orientation or equilibrium

How can humans become infected with Clonorchis sinensis (liver fluke)? How do those organisms become infected with it? Where will these reside in humans? What does it cause?

People become infected by eating infected raw or under-cooked fish containing the larvae. After being ingested by humans, the larvae grow into adult worms and live inside the human bile duct system. The life cycle takes three months to complete in humans. Snails ingest the eggs, eggs release miracidia which go through developmental stages until they become cercariae (free-swimming) and then they are released from the snail. They then encyst in the skin or flesh of freshwater fish. The fish with these cercariae are ingested by humans. Causes liver disease (cirrhosis), found in Asia.

What is the meaning of the term "platyhelminthes"? In the Phylum Platyhelminthes what has replaced the mesoglea?

Platyhelminthes: Flat worms Mesoglea replaced by mesodermal layer

Which of the dimorphic forms is considered a persistent larval or juvenile stage?

Polyp stage

Pneumatophore is found in what jellyfish?

Portuguese Man of War

Why is this morphological development more of an advantage for this type of organism?

Quicker response to stimuli, more precise movement

What are flame cells? What organ do we believe these eventually developed into?

Regulates marconutrients through the body. Kidney?

What is another name for the Phylum Nemertea? What are the general characteristics of the Nemertine worms? What is the difference between the two classes found in this phylum?

Ribbon worm,have a long retructable proboscis complete digestive system & circulatory system, locomotion- muscles by expanding motion "snake like", most are marine few freshwater. Two Classes Enopla- with dagger and Anopla- without dagger

What has a rotating corona of cilia?

Rotifers.

Of the three different subclasses found in the Class Trematoda which is considered to be the most important and why?

Schistosoma, blood flukes, causes a major human disease called schistosomiasis (bilharziasis).

What is the genus of blood flukes? Why would we care about this? Who is the indirect carrier to this? How do humans become infected? How have we attempted to prevent further infections?

Schistosoma.

Be able to identify the following features of the tapeworm: scolex, germinative zone, mature proglottid, gravid proglottid and strobila.

Scolex- head for attachment with hook or suckers. Germinative zone- Mature proglottid- both male and female reproductive systems Gravid proglottid- produce eggs (a big o' bag of eggs) Strobila- total 3-4k

To which Class do the true jellyfish belong?

Scyphozoa

Advantages of radial symmetry?

Sensors around the whole body, easier to catch prey and avoid predators

How do turbellarians excrete solid waste? Liquid waste?

Solid waste is throw up. Liquid is pushed out

What are the two main subclasses of the Class Cestoda and what is the primary differences (monozoic and polyzoic)?

Subclass cestodaria- monozoic, 10 hooks Subclass eucestoda- polyzoic, multiple reproductive sets, 6 hooks, more common

What are the three main components to flatworms nervous system? What is another name for their "brain"?

The lateral nerve cord, the transverse nerve, and ? Ganglia

What are the similarities and differences between the Ctenophorans and Cnidarians.

The main difference between Cnidaria and Ctenophora is that Cnidaria exhibits radial symmetry whereas Ctenophora exhibits biradial symmetry. Both cnidarians and ctenophores are diploblastic animals. Tentacles occur around the mouth of both cnidarians and ctenophores

Briefly describe the structure of a polyp.

The mouth and surrounding tentacles of polyps face upward, and the cylindrical body is generally attached by its opposite end to a firm substratum.

What is strobila?

The segmented part of the body of a tapeworm that consists of a long chain of proglottids

What type of symmetry do the Cnidarians and Ctenophorans have? How is this type of symmetry an advantage for these organisms?

They are radially symmetrical. They can not move left or right or back, but have body sense organs around the whole organism allowing them to sense danger from their prey from any direction.

Explain why your textbook says that although the polyp and medusa seem different, they are actually very similar.

They have similar structures. They both have tentacles near the mouth, have a gastrovascular cavity, have epidermis, have mesoglea, and have a gastrodermis.

Why are muscle fibers important to planaria?

They help in regeneration, rapidly improving regeneration after amputation and with great precision through the proliferation and differentiation of pluripotent stem cells.

What is the term that refers to organisms that have three germ/developmental layers(ectoderm, endoderm, and mesoderm).

Triploblastic

What is one of the main differences between turbellarians and the trematodes and cestodes?

Turbellarians: Ciliated epidermis with rhabdites and dual-glands, primary on belly side The other 3 have: Syncytial tegument

What is the shape of endoprocta?

Unique because of their bowling pin shape

Describe or diagram the main parts of a cnidocyte that I discussed in class. How can they be triggered? Briefly describe what occurs when a cnidocyte is triggered.

When triggered these cells shoot out a discharge thread which can entagle and or poisen its intended prey. It is triggered by either touch and chemically.

Are Planaria found in freshwater?

YES

Can jellyfish have adhesive pads?

YES, Gonionemus

Can Cnidaria be found in freshwater?

YES, Hydrozoan

Explain the difference between Zoantharian and Octocorallia corals.

Zoantharian-exoskeleton, Septa arranged in multiples of six and stony or true corals Octocorallia- internal skeleton, soft or horny corals, all are colonial, body walls are connected

Why does your text believe that the cnidarians and ctenophorans may not have a shared ancestry with bilateral animals?

because of the motor proteins mainly the location and the functions of the proteins differ and so it suggests a convergent evolution not common ancestry

Know the typical hosts of cestodes listed in Table 8.2

beef tapeworm, pork tapeworm, fish tapeworm, dog tapeworm, dwarf tapeworm, unilocular hydatid, multilocular hydatid

Why is the Phylum Mesozoa important? What is the primary differences between the Rhombozoans and Orthonectids found in this class?

considered the "missing link" between protozoa and metazoan; Rhomabozoans live in kidneys of cephalopods and Orthoectids has plasmodium cell mass, leading to asexual reproduction

What is the term "sexual dimorphism?

distinct difference in size or appearance between the sexes of an animal in addition to difference between the sexual organs themselves.

In what group of organisms can you find Acanthocephala? What is the main damage caused by these worms?

endoparasites of vertebrates 1100 ( fish, birds, and mammals)

Describe different types of cells found in the epidermis and gastrodermis of the hydra.

epidermis has : epitheliomuscluar cells- helps with contraction of fibrils shortens the body and tentacles. interstital cells- stem cell gland cell- secrete mucus or adhesive material Cnidocytes, nerve cell, sensory cells. Gastrodermis has: consists of manily large, ciliated, columnar epithelial cells with irregular flat bases.

When was the Phylum Cycliophora first described? Where do you find the cycliophorans and how many species are there? What do they feed on?

first described in 1995.

Describe some of the symbiotic relationships of the sea anemone.

fish ie. (clown fish) , algae, crabs

Describe the different types of coral reefs.

fringing: close to coast, smooth no start or stops. Barrier: close to coast, more prominent starts & stops Atoll: round, caused by the island being surrounded by reefs.

What is unique about the genus Gonionemus?

has a adhesive pad

How does your text explain some of shared characteristics between these two groups?

have a range of contractile elements and true muscle cells have the same two filaments, they also both lack mesodermal layer

Describe the comb plates. What is the function of the comb plates?

many cilia together and the function is that its the means of locomotion.

List, in order, the basic components of the "typical" digestive system found in the turbellarians (slide 8 of chapter 8).

mouth, pharynx, and intestine

Class Myxozoa are what type of parasites? What is unique about them? Why should we care?

obligate parasites to fish and worms. causes host to exhibit strange behaviour (whirling disease). bad for commercial & sport fisheries

What is the function of the statocyst?

orientation

What other name are the ectoprocta often called? What are the general characteristics of the Phylum Ectoprocta? Why should we care about them? What structure of theirs has provided a solid fossil record?

other name is Bryozoans ()aquatic colonial organisms that often attach to a hard substrate ()most are sessile ()ciliated crown of tentacles with toxin we should care about them because they have medical value.

Describe different types of movements found in the hydra.

sessile