Biology Chapter 28 Study Guide

"The sessile polyp form has, in fact, two types of polyps they are"

"gastrozooid, gonozooid

"Mesenteries do not divide the gastrovascular cavity completely which aids in

"increased surface area for absorption of nutrients and gas exchange"

"Even other species are solitary polyps "

(Hydra) or solitary medusae (Gonionemus)

" Nearly all _____________cnidarians are marine species."

(about 99 percent)

"Cubozoa species may achieve sizes of"

15-25 cm

"Class Scyphozoa includes all the jellies and is exclusively a marine class of animals with about "

200 known species

"Hydrozoa includes nearly____________; most are marine, although some freshwater species are known"

3,200 species

"The phylum Cnidaria contains about 10,000 described species divided into four classes:"

Anthozoa, Scyphozoa, Cubozoa, and Hydrozoa

"The presence and composition of spicules/spongin are the differentiating characteristics of the three classes of sponge"

Calcarea, Hexactinellida,Demospongia

"Phylum ____________ includes animals that show radial or biradial symmetry

Cnidaria

"Members of the species Scyphozoan, range from 2 to 40 cm in length but the largest scyphozoan species,

Cyanea capillata, can reach a size of 2 m across

"______________is an extracellular matrix consisting of a collagen-like gel with suspended cells that perform various functions"

Mesohyl

"The simplest of all the invertebrates are the

Parazoans

"Colonies may also be free-floating and contain medusoid and polypoid individuals in the colony as in "

Physalia (the Portuguese Man O' War) or Velella (By-the-wind sailor

"____________which are epithelial-like cells, form the outermost layer of sponges and enclose a jelly-like substance called mesohyl."

Pinacocytes

"Which of the following statements is false?

Pinacocytes can transform into any cell type.

The Parazoans are only founds in the phylum

Porifera or sponges

"Sponges exhibit a range of diversity in body forms, including variations in the size of the_________ the number of ___________, and where the cells that filter food from the water are located."

Spongocoel, osculi

"Many hydrozoans form colonies that are composed of __________________________, such as in the colonial hydroid Obelia."

a branched colony of specialized polyps that share a gastrovascular cavity

"Gemmules are capable of attaching to . "

a substratum and generating a new sponge

"Gemmules are environmentally resistant structures produced by ."

adult sponges wherein the typical sponge morphology is inverted

"The second crucial cells in sponges are called _____________, named for the fact that they move throughout the mesohyl in an amoeba-like fashion"

amoebocytes (or archaeocytes)

"Some sea anemones establish a mutualistic relationship with hermit crabs by attaching to the crab's shell

and gathering food particles for the creature when it feeds and is return is protected by the stingers cells

"The ___________, the sea anemones and corals, are all sessile species,"

anthozoans

"The scyphozoans (jellyfish) and cubozoans (box jellies)."

are swimming forms

"Sponges are generally sessile "

as adults and spend their lives attached to a fixed substratum

"With gemmules the collagen that is normally found in the mesohyl "

becomes the outer protective layer

"Scyphozoans display a characteristic "

bell-like morphology

"Cubozoa includes jellies that have a "

box-shaped medusa, or a bell that is square in cross-section

"Class Calcarea contains "

calcium carbonate spicules and no spongin

"Sea anemones are usually brightly colored and "

can attain a size of 1.8 to 10 cm in diameter

"Structures such as enable water to move through the sponge to nearly all body cells.

canals, chambers, and cavities

"In freshwater sponges, gemmules may survive hostile environmental conditions like."

changes in temperature and serve to recolonize the habitat once environmental conditions stabilize

"There are similarities in appearance between the sponge

choanocyte and choanoflagellates (Protista)

"Bacteria smaller than 0.5 microns in size are trapped by

choanocytes, which are the principal cells engaged in nutrition

"____________are present at various locations, depending on the type of sponge, but they always line the inner portions of some space through which water flows

choanocytes; (collar cells)

"The similarity in appearance suggests that sponges and choanoflagellates are

closely related and likely share a recent common ancestry"

" The outer wall of the cell (Cnidocytes) has hairlike projections called

cnidocils, which are sensitive to touch.

"Cnidarians contain specialized cells known as

cnidocytes ("stinging cells") containing organelles called nematocysts (stingers)."

Lophocytes secrete

collagen

"Collencytes and lophocytes, which produce the "

collagen-like protein to maintain the mesohyl

"An example of a polymorphic cnidarians is the "

colonial hydroid called an Obelia.

"Spicules are most conspicuously present in class Hexactinellida, the order "

consisting of glass sponges

The most venomous group of all jellies

cubozoans

"The polyp form in these animals often shows a "

cylindrical morphology with a central gastrovascular cavity lined by the gastrodermis.

"Amoebocytes have a variety of functions:

delivering nutrients from choanocytes to other cells within the sponge, giving rise to eggs for sexual reproduction (which remain in the mesohyl), delivering phagocytized sperm from choanocytes to eggs, and differentiating into more-specific cell types"

"Since gemmules can withstand harsh environments, are resistant to "

desiccation, and remain dormant for long periods, they are an excellent means of colonization for a sessile organism

"Sponge draw water through "

diffusion

"Sponges lack complex

digestive, respiratory, circulatory, reproductive, and nervous systems.

"Choanocytes will differentiate into sperm for sexual reproduction, where they will become

dislodged from the mesohyl and leave the sponge with expelled water through the osculum."

"The mouth leads to the gastrovascular cavity, which may be sectioned into four interconnected sacs, called "

diverticuli

"The cumulative effect of the flagella from all choanocytes aids the movement of water through the sponge:

drawing water into the sponge through the numerous ostia, into the spaces lined by choanocytes, and eventually out through the osculum (or osculi)."

"Each mesentery consists of one

ectodermal and one endodermal cell layer with the mesoglea sandwiched in between"

"All cnidarians show the presence of two membrane layers in the body that are derived from the ."

endoderm and ectoderm of the embryo

"The true characteristic shared by all of these diverse species is that their gonads for sexual reproduction are derived from

epidermal tissue, whereas in all other cnidarians they are derived from gastrodermal tissue

"The outer layer (from ectoderm) is called the , "

epidermis and lines the outside of the animal

"The gonads in Scyphozoa are formed from the gastrodermis and gametes are"

expelled through the mouth.

"The cnidarians perform _____________ in which the food is taken into the gastrovascular cavity, enzymes are secreted into the cavity, and the cells lining the cavity absorb nutrients"

extracellular digestion

"In other sponges, ostia are formed by

folds in the body wall of the sponge.

"When the reproductive buds mature, they break off and become."

free-swimming medusa, which are either male or female (dioecious)

" Medusa forms are motile, with the mouth and tentacles hanging down "

from an umbrella-shaped bell

"The inner layer (from endoderm) is called the . "

gastrodermis and lines the digestive cavity

"The ___________ has only one opening that serves as both a mouth and an anus, which is termed an incomplete digestive system."

gastrovascular cavity

____________ which is adapted for capturing prey and feeding of medusa

gastrozooid

"An atypical type of asexual reproduction is found only in freshwater sponges and occurs through the formation of."

gemmules

_____________are adapted for the asexual budding of medusa

gonozooid

All sponges do not display tissue level organization except

hexactinellids

"These cells (Cnidocytes) are present around the mouth and tentacles, and serve to "

immobilize prey with toxins contained within the cells

"Sea anemones feed on small fish and shrimp, usually by."

immobilizing their prey using the cnidocytes

"The most well-known medusoid animals are the ."

jellies (jellyfish)

"Whereas pinacocytes line the outside of the sponge, choanocytes tend to ______________ that surround the mesohyl"

line certain inner portions of the sponge body

"The mouth cavity of sea anemone is divided into several chambers by longitudinal septa called"

mesenteries

"The gastrodermis and epidermis Hydrozoa's have a simple layer of __________ sandwiched between them"

mesoglea

"Between these two membrane (epidermis and gastrodermis) layers is a non-living, jelly-like ."

mesoglea connective layer

"The cell body is embedded in mesohyl and contains all organelles required for normal cell function, but protruding into the "open space" inside of the sponge is a mesh-like collar composed of "

microvilli with a single flagellum in the center of the column

"The limit of this type of digestion (diffusion) is that food particles

must be smaller than individual cells.

"___________ contain coiled threads that may bear barbs."

nematocysts

"Some of the spicules may attain giant proportions (in relation to the typical size range of glass sponges""

of 3 to 10 mm) as seen in Monorhaphis chuni, which grows up to 3 m long

"Water entering the spongocoel is extruded via a large common opening called the "

osculum

"In addition to the osculum, sponges have multiple pores called____________on their bodies that allow water to enter the sponge"

osita

"The cubozoans contain muscular pads called ___________ at the corners of the square bell canopy, with one or more tentacles attached to each ________"

pedalia, pedalium

"Particles that are larger than the ostia may be "

phagocytized by pinacocytes

"Some cnidarians are __________, that is, they have two body plans during their life cycle"

polymorphic

"The class Anthozoa includes all cnidarians that exhibit a."

polyp body plan only; in other words, there is no medusa stage within their life cycle

"Animals in this phylum (Cnidaria) display two distinct morphological body plans:

polyp or "stalk" and medusa or "bell

"Animals in this class are polymorphs, and most exhibit both

polypoid and medusoid forms in their lifecycle, although this is variable

"Cubozoans exist in a "

polypoid form that develops from a planula larva

" In some sponges, ostia are formed by _________, single tube-shaped cells that act as valves to regulate the flow of water into the spongocoel"

porocytes

"Anthozoans remain polypoid throughout their lives and can reproduce asexually by budding or fragmentation, or sexually by producing gametes. Both gametes are"

produced by the polyp, which can fuse to give rise to a free-swimming planula larva

"Sponges may also become sequentially hermaphroditic"

producing oocytes first and spermatozoa late

Choanocytes have flagella that

propel water through the body.

"Neurons may even be present in clusters called "

rhopalia

"The spongocoel in simple sponges, canals within the body wall in more complex sponges, and chambers "

scattered throughout the body in the most complex sponges

"Planula larvae are formed by external fertilization; they settle on a substratum in a polypoid form known as ."

scyphistoma

"Cubozoans display overall morphological and anatomical characteristics that are similar to those of the."

scyphozoans

"Examples of Anthozoa's include

sea anemones sea pens, and corals, with an estimated number of 6,100 described species."

"Polyp forms are__________ as adults, with a single opening to the digestive system (the mouth) facing up with tentacles surrounding it"

sessile

"The mouth of a sea anemone is surrounded by tentacles that bear cnidocytes lined by grooves called

siphonophore

"Class Hexactinellida contains "

six-rayed siliceous spicules and no spongin

"Sclerocytes, which produce"

spicules in some sponges

"In some sponges, sclerocytes secrete small _______________, which are composed of either calcium carbonate or silica, depending on the type of sponge. "

spicules into the mesohyl

"Class Demospongia contains"

spongin and may or may not have spicules; if present, those spicules are siliceous

"Spongocytes, which produce the protein "

spongin in the majority of sponges

"The morphology of the simplest sponges takes the shape of a cylinder with a large central cavity, the

spongocoel

"Spicules serve to provide additional "

stiffness to the body of the sponge and ward off predators

"In gemmules, an inner layer of amoebocytes is ."

surrounded by a layer of collagen (spongin) that may be reinforced by spicules

"The hydrozoans contain sessile forms and"

swimming colonial forms like the Portuguese Man O' War

Cnidaria are diploblastic, that is,

they develop from two embryonic layers

"Parazoans ("beside animals") do not display

tissue level of organization

"Anemone fish, or clownfish, are able to live in the anemone since they are immune to the"

toxins contained within the nematocysts

"The structure of a choanocyte is critical to its function, which is to generate a water current through the sponge and to "

trap and ingest food particles by phagocytosis

"The gel-like consistency of mesohyl acts like an endoskeleton and maintains the _________________ of sponges."

tubular morphology

"In the jellyfish, a mouth opening is present on the "

underside of the animal, surrounded by tentacles bearing nematocysts

"Sponges food is trapped when

water passes through the ostia and out through the osculum.

Porocytes control the flow of

water through pores in the sponge body.

"Sponges are monoecious (hermaphroditic), ."

which means that one individual can produce both gametes (eggs and sperm) simultaneously