Quiz 3: Cnidarians, Molluscs, and Sponges

List 3 characteristics that define animals.

1. All animals eat. 2. All animals have a blastula (when egg and sperm come together, the cells eventually differentiate as more cells develop, at one point early in development, cells ball up and that ball becomes hallow in animals). 3. All animals are multicellular.

List the 3 different types of body symmetry found in Kingdom Animalia.

1. Asymmetry (no symmetry) 2. Radial symmetry 3. Bilateral symmetry

List the 4 classes within Phylum Cnidaria write down the scientific name as well as what types of animals are in each group ( note - I won't force you to memorize those class names, but you will need to recognize that there are 4 groups and the characteristics of each group that differentiate them).

1. Class Syphozoa (jellyfish) 2. Class Cubozoa (cube jellies, sea wasps) 3. Class Hydrozoa (hydroids) 4. Class Anthozoa (anemones, stony and soft corals)

Provide at least 3 examples of mutualistic symbiosis that includes a cnidarian. Identify each of the 2 organisms involved within each symbiosis and state what each gains.

1. Clownfish and the anemone: the fishes live in toxic anemone and they coat their bodies in the stingers so they are resistant to the anemone. The clownfish will defend the anemone, and the clownfish gets to live in the anemone. 2. Portuguese man o war and fish: Portuguese man o war has stingers, and the fish hang out in the stingers, other fish swim by and think the stingers are safe, the new fish dies, because it is stung by stingers, and the Portuguese man o war and resistant fish eat the seas fish. 3. Anemone and hermit crab: hermit crab has a shell, but then the anemone latches on and the crab has to walk around with anemone. The anemone gets to feed more since they get to move with the crab and get food from the water current. The hermit crab gets protected by the anemone.

Provide at least 3 examples of mutualistic symbiosis that includes a cnidarian. Identify each of the 2 organisms involved within each symbiosis and state what each gains.

1. Coral and Dinoflagellates: dinoflagellates photosynthesis's, provide coral with extra food and protein. Dinoflagellates live in the corals. 2. Clownfish and anemone: the fishes live in anemone and they coat themselves in the toxic stingers of the anemone so they are resistant, they protect the anemone and defend it. 3. Portuguese man o war and fish: there is a fish that lives in the stingers of the Portuguese man o war because it is resistant to the frilly stingers. The fish tricks other fish into thinking the frills are a good place to hide, the other fish dies, Portuguese man o war and fishes eat.

List the 5 Classes of Molluscs, stating what types of animals each is (again, you don't need to worry about the scientific names, but they are actually quite descriptive, so I recommend learning them and recognizing why the name helps you differentiate the animals.) We'll explore these classes in lab next week.

1. Gastropoda: snails, limpets 2. Bivalvia: clams, mussels, scallops 3. Cephalopoda: octopus, squid, cuttlefish, 4. Nudibranchs: sea slugs 5. Polyplacophora: chitons

List the 4 types of cells that sponges have and give a brief statement of the function(s) of each one.

1. Porocytes: create pores 2. Pinacocytes: the skin 3. Choanocytes: collarcells (create currents, catch food) 4. Amoebocytes: amoebas are the cells that move around a lot. They will go up the choanocyte, take food, deliver food, deliver food to other cells in sponge, help w/reproduction, structure

Approximately what percentage of animal species are invertebrates?

97%

Define what a radula is, where it is, and its purpose.

A feature unique to molluscs is the radula, a ribbon of small teeth that is used to feed, usually by rasping food from surfaces (Fig. 7.22). The radula is modified in carnivorous molluscs (Figs. 7.23 and 7.24c). The radula is made largely of chitin, a highly resistant carbohydrate also found in other invertebrates.

View the video description of the life cycle of jellyfish that is posted in Canvas, be able to describe it - you don't need to know the specific terms, but you need to describe/explain and state what 'alternation of generations' means.

As an adult they are a Medusa, have row of tentacles that have stinging cells, have 4 oral arms. Have 4 gastric pouches. When females are mature, release eggs down, fertilized eggs remain on oral arms until ready to hatch. Start off as larva. Small little floating circle, they become a polyp, polyp begins asexual reproduction, they clone itself, each clone, the one at the top pops off, becomes an ephyra, and then a Medusa as it matures. Alternation of generations is when a plant or organism asexually reproduces and sexually reproduces.

List 3 different ways that anthozoans can reproduce asexually, and describe how they sexually reproduce.

Asexual reproduction: 1. Fission & Pinching: anemone pulls itself in half to reproduce. 2. Pedal laceration: anemone moves and leaves behind a small amount of tissue that eventually grows to be full size. 3. Budding: little babies grow off side, eventually they move away. Asexual reproduction is fast, you know they will survive in same environment because they are genetically the same. Sexual methods: 1. Broadcast spawning: the organism releases eggs into the water that float away and hopefully the eggs meet with some sperm that was releases by another organism somewhere else, so they hopefully will meet up and fertilize and turn into larvae. Hopefully they land somewhere safe.

Are sponges symmetrical or asymmetrical?

Asymmetrical

Define 'biogenic habitat' and explain what that means in terms of a coral reef.

Biogenic habitat: ecosystem created by a living organism. Coral reefs are created by cnidarians, so they are biogenic habitats.

Define tissue.

Cells of one kind working together for a function.

What level of biological organization do cnidarians have?

Cnidarians are radially or biradially symmetric, a general type of symmetry believed primitive for eumetazoans. They have achieved the tissue level of organization, in which some similar cells are associated into groups or aggregations called tissues, but true organs do not occur.

Briefly describe the sensory system of Cnidarians. Describe the structure and function of cnidocytes (nematocysts).

Cnidarians capture small prey by discharging their nematocysts (or cnidae), unique stinging structures found within cnidocytes, specialized cells in the tentacles

Define polyp & medusa. Draw them and label the parts. Provide examples of each within Phylum Cnidaria.

Cnidarians occur in two basic forms (Fig. 7.7): a polyp, a sac- like attached stage with the mouth and tentacles oriented upward, and a bell-like medusa (commonly known as jellyfish, or sea jelly), which is like an upside-down polyp adapted for swimming. The life history of some cnidarians includes both polyp and medusa stages. Others spend their entire lives as either polyp or medusa.

List the 4 cell structures that prokaryotes and eukaryotes (ie ALL cells) share.

DNA, Ribosomes, cytoplasm, and plasma membrane

Briefly describe 2 ecological roles of sponges and 2 ways in which humans use them.

Ecological roles: 1. They filter water. 2. They act as prey, since turtles and mollusks eat them. 3. Sponges can create reefs where organisms take advantage of the 3 dimensional habitats to hide. How humans use them: 1. Humans harvest sponges to clean things, they use them as sponges. 2. Humans use them to create treatments for cancer, they act as the source for the HIV treatment, AZT, they are being used in Ebola and COVID 19 treatment

State which Kingdoms of organisms are eukaryote and which are prokaryote.

Eukaryote: Plantae, Animalia, Fungi, Protista Prokaryote: Eubacteria, Archaebacteria

Within a hydroid colony there is some differentiation among the polyps for different functions. List the 2 key functions in all hydroids, and the extra 2 in the Portuguese-man-o'-war. Again, you don't have to worry about the scientific terms but do know the functions.

Feeding polyp and reproductive polyp. In the Portuguese man o war, there is the gas filled polyp to help it keep afloat, and the gastrozooids polyp, which helps with digestion.

Describe the basic structure of animals within the Phylum Mollusca. Be able to identify & define the function of each of the following parts: head, foot, visceral mass, mantle, mantle cavity, mouth, anus, gills.

Head Foot: bottom of snail, used in locomotion Visceral mass:covered with soft ephithelium Mantle: dorsal wall that covers organs of digestion, reproduction, and movement. Produces shell Mantle cavity: formed by mantle skirt, encloses a water space. Contains mollusc's gills, anus. Acts as a respiratory chamber Anus: in internal space Mouth Gills

Briefly describe what the biological classification system does. List the 8 levels of it, in order from most general to most specific.

Help to define organisms that all people can recognize. Stops any confusion so people know exactly what organism they are talking about. Called the current system of classification which uses eight taxa. Domain Kingdom Phylum Class Order Family Genus Species

Define bioerosion. Provide an example involving a sponge.

In the process, these and many other grazers remove bits of calcium carbonate from the reef to form sediment. The erosion caused by such organisms, or bioerosion, tends to wear the reef away. Marine bio erosion can be caused by sponges, the sponges can burrow into other things and became a part of the coral they burrowed into.

What does it mean that some cnidarians (Jellies & hydroids) have 'alternation of generations'?

It means that in one generation, they change a lot in terms of structure. For instance, as a fully grown jellyfish, the jellyfish is known as a Medusa. However, when the jellyfish reproduces, they start off as a tiny zygote, then turn into planula (baby version of fully grown animal, looks very different from adult version of animal), the becomes a living organism living in the ground called a polyp, which looks like a plant. Then the grounded polyp asexually reproduces and clones itself, which is called a strobila. Then, the tops of the little clones bounce off and grow, they are called ephyra. Finally, the ephyra grows and becomes a fully formed Medusa again. This all happens in one Medusa's life cycle.

The mantle cavity is an important area of the body of most molluscs. Describe what this is (how it is created) and how and why water flow is created in this area.

Mantle creates mantle cavity. It's the internal space that has gills and anus. Water enters through siphons and cephalopods swim by forcing water out of the mantle cavity through the siphon.

What is the mantle? What are 2 functions of it?

Mantle is below shell of molluscs. Mantle: dorsal wall that covers organs of digestion, reproduction, and movement. Produces shell. Mantle is thin layer of tissue protects body, protects shell.

Hydroids are clonal colonial animals. Explain what that means.

One individual clones itself to create the hydrozoids. Some of them are called the feeding polyps in which they catch food and push the food in so that the hydrozoan can digest it. Other polyps are reproductive, and that is there role. But they all come from the same hydrozoan.

Re-cap: Be sure you know the basic body plan of cnidarians including what a polyp and a medusa are, how many true tissue layers there are (define: epidermis, gastrodermis, and mesoglea), what type of body symmetry they have (and what that means), and in addition to their basic body plan, what is the unique feature that defines this phylum (define cnidocyte)

Polyp: attached to the ground, part of the Medusa's life cycle. Medusa: fully grown polyp, what people think of when they think of a jellyfish. There are technically 2 tissue layers. Epidermis: outside layer (skin) Gastrodermis: inside layer (gut) Mesoglea: in between the epidermis and gastrodermis, it is the jelly that is digestive. Bilateral symmetry. Like humans. Their unique feature is that they can sting.

How do eukaryotes differ from prokaryotes in terms of cell structure and DNA?

Prokaryotes: The DNA floats around in the cell. Has a nucleoid, cell wall, capsule, flagellum, ribosomes, and cell membrane. One room. Eukaryotes: Has a nucleus for DNA (has a compartment for DNA). Has cell membrane, ribosomes, chloroplast, golgi, mitochondrian, cytoplasm, cytoplasmic membrane, nucleus, nucleolus, and endoplasmic reticulum. Whole house with separate rooms.

What type of symmetry do Cnidarians have? What advantage does this have?

Radial symmetry, which allows them to have a 360 degree density system, can't sneak up on them. They are constantly aware of their surroundings.

What does the Tree of Life illustrate?

Shows all things have a common ancestor. All organisms that come out of the common ancestor are adaptations. They get more complex. Shows the concept that there are evolutionary relationships in the history of living organisms.

Explain the similarities and differences among anemones, soft corals, and 'true'/stony corals differ from each other.

Soft corals have soft and feathery tentacles, hard corals have hard corals. They are in different orders, but share the same class and subclass.

Most molluscs have a trochophore larvae, but this larval stage is not unique to molluscs. What other groups share this larval form? What does this say about these two groups of animals evolutionarily?

Some molluscs have a trochophore larva like polychaetes, a characteristic often used as evidence for close affinities between molluscs, the segmented worms, and other groups. In gastropods and bivalves the trochophore usually develops into a veliger, a planktonic larva that has a tiny shell (see Fig. 15.11a). In many gastropods, however, part or all of development takes place within strings or capsules of eggs.

What is a spicule within sponges? What functions do they serve? What are they made out of?

Spicules are a part of the structure of a sponge. They help structure the sponge and defend the sponge from predators, since they are spikey. They are made of C0CO3.

All sponges are sessile - define that.

Sponges are fixed in one place, attached directly by its base. Immobile.

What level of biological organization do sponges have?

Sponges have cellular-level organization, meaning that that their cells are specialized so that different cells perform different functions, but similar cells are not organized into tissues and bodies are a sort of loose aggregation of different kinds of cells.

What & how do sponges eat? How does the name Porifera relate to that?

Sponges suck their food in when water enters the sponge, since the water has the food in it. They strain food particles from water. They eat bacteria and protists. The food enters in through their pores called Ostia (the openings on the body of the sponge). The name porifera is the phylum that sponges are in and it means pores, since the sponges whole body has pores.

Define: symbiosis, mutualism, commensalism, parasitism.

Symbiosis- close and often long-term interaction between two different species Mutualism- a symbiotic relationship in which both organisms benefit. Commensalism- A symbiotic relationship in which one organism benefits and the other organism is not helped nor harmed Parasitism- A symbiotic relationship in which one organism is helped and the other organism is harmed.

Describe the basic structure of jellyfish (Class Scyphozoa) by using the moon jelly as an example: what are those 4 longer 'tentacles' that hang down called? What are they used for? What are those 4 lobes you can see inside the jelly?

The moon jelly has a structure that looks like a four leaf clover in the center of its head, and they are called the gastric pouches. They create more surface area, and they serve as the stomach and reproductive organs. The 4 longer tentacles are called the oral tentacles, and they help the jelly grab food. They have one opening, where they infuse food in, get waste out, sex cells go out.

Describe some key body plan characteristics of Class Anthozoa (anemones, etc).

They are known as the flower animal. 1. No Medusa stage. 2. Sessile adults: so they are attached to substrate. They do not swim. 3. Solitary or colonial reproduction. Can reproduce alone or not alone. More complex polyp, gut septa.

List 2 characteristics of Phylum Mollusca that are unique to this Phylum.

They have a radula. The body has a head, foot, visceral mass.

Some hydroids, like Fire coral differ from most other hydroids, how so?

They secrete a bit of a calcium carbonate stony skeleton, which makes them look like a coral, even though they technically aren't corals. Thus, they are called hydrocorals. They are in the class hydrozoa.

List an example of a predator of each of the following groups: jellies, of hydroids, and of corals.

Turtles will eat jelly fish. Seas slug will eat hydrozoans and steal their stingers to protect itself. The bump head fish will ram into coral reef and eat the corals.

List and define the 3 'layers' of a Cnidarian - this includes 2 tissue layers plus the 3rd (not true tissue). Draw a cnidarian and label each layer.

Two layers of cells form the body wall of cnidarians. One of these, the epidermis (see Figs. 7.7 and 7.10), is external, whereas the other, the gastrodermis, lines the gut. There is also a narrow, gelatinous middle layer, or mesoglea, that usually doesn't con- tain cells. In medusae this layer is expanded to form a gelatinous, domed bell, hence their common name of jellyfish, or sea jelly.

Some molluscs have a siphon. How are siphons formed? What purposes does it serve?

Water enters through the free edge of the mantle and leaves through the siphon, or funnel, a muscular tube formed by what remains of the foot, which projects under the head. Cephalopods swim by forcing water out of the mantle cavity through the siphon.

Define invertebrate & vertebrate

vertebrates:have a backbone (a row of bones called vertebrae) invertebrates: animals without a backbone.