BIO 212 Practical Test Questions Answered Correctly Rated A+
Phylum Porifera - Answers Sponges are animals of the phylum Porifera. They are multicellular
organisms that have bodies full of pores and channels allowing water to circulate through them,
consisting of jelly-like mesohyl sandwiched between two thin layers of cells
Phylum Cnidaria - Answers Jellies. Cnidaria is a phylum containing over 10,000 species of
animals found exclusively in aquatic and mostly marine environments. Their distinguishing
feature is cnidocytes, specialized cells that they use mainly for capturing prey.
Class Desmospongea - Answers The Demospongiae are the largest class in the phylum Porifera.
Their "skeletons" are made of spicules consisting of fibers of the protein spongin, the mineral
silica, or both.
Class Hexactinellida - Answers Phylum Porifera. Hexactinellid sponges are sponges with a
skeleton made of four- and/or six-pointed siliceous spicules, often referred to as glass sponges,
they are notable for their long life of 1000s of years.
Class Hydrozoa - Answers Phylum Cnidaria. Hydrozoans or "water animals". They are very small
predatory animals that can be either marine or freshwater, but mostly saltwater. There are about
3200 species belonging to the taxonomic class, which is fairly large. Some examples of
hydrozoans are the freshwater jelly (Craspedacusta sowerbyi), freshwater polyps (Hydra),
Obelia, Portuguese man o' war (Physalia physalis), chondrophores (Porpitidae), "air fern"
(Sertularia argenta), and pink-hearted hydroids (Tubularia).
Order Hydroida - Answers Phylum Cnidaria. Class Hydrozoa. an order of Hydrozoa comprising
forms alternating a well-developed asexual polyp generation with a generation of free medusae
or of abortive medusoid reproductive structures on the polyps — see leptomedusae
Order Chondrophora - Answers Phylum Cnidaria. Class Hydrozoa. They all live at the surface of
the open ocean, and are colonies of carnivorous, free-floating hydroids whose role in the
plankton community is similar to that of pelagic jellyfish. The chondrophores look like a single
organism but are actually colonial animals, made up of orderly cooperatives of polyps living
under specialized sail-structures.
Order Siphonophora - Answers Phylum Cnidaria. Class Hydrozoa. Although a siphonophore
appears to be a single organism, each specimen is actually a colony composed of many
individual animals. Most colonies are long, thin, transparent pelagic floaters. Some
siphonophores superficially resemble jellyfish. The best known species is the dangerous
Portuguese man o' war (Physalia physalis). With a body length of 40-50 m (130-160 ft), another
species of siphonophore, Praya dubia, is one of the longest animals in the world.
Order Milleporina - Answers Fire corals are colonial marine organisms that look rather like real
coral. Technically they are not corals, since they are more closely related to Hydra and other
hydrozoans. They are members of the phylum Cnidaria, class Hydrozoa, order Capitata, family
, Milleporidae. --- The very small nematocysts on fire corals contain tentacles that protrude from
numerous surface pores (similar to jellyfish stings). In addition, fire corals have a sharp,
calcified external skeleton that can scrape the skin.
Class Scyphozoa - Answers The Scyphozoa are a class within the phylum Cnidaria, sometimes
referred to as the "true jellyfish". The class name Scyphozoa comes from the Greek word
skyphos (σκύφος), denoting a kind of drinking cup and alluding to the cup shape of the
organism.
Class Anthozoa - Answers Corals. Anthozoa is a class within the phylum Cnidaria. Unlike other
cnidarians, anthozoans do not have a medusa stage in their development. Instead, they release
sperm and eggs that form a planula, which attaches to some substrate on which the cnidarian
grows. Some anthozoans can also reproduce asexually through budding. More than 6,100
species have been described.[1]
Subclass Hexacorallia - Answers Hexacorallia is a subclass of Anthozoa comprising
approximately 4,300 species of aquatic organisms formed of colonial polyps generally with 6-
fold symmetry. This includes all of the stony corals, which are vital for coral reef formation, as
well as all sea anemones, tube anemones, and zoanthids, ranged within six extant orders.[1] The
hexacorallia are distinguished from the other subclass of Anthozoa, Octocorallia, in having six
or fewer axes of symmetry in their body structure and only single rows of tentacles. These
organisms are formed of individual soft polyps which in some species live in colonies and can
secrete a calcite skeleton. As with all Cnidarians, these organisms have a complex life cycle
including a motile planktonic phase and a later characteristic sessile phase. Hexacorallia also
include the significant extinct orders of the rugose corals and tabulate corals
Order Actinaria - Answers Sea anemones are a group of water-dwelling, predatory animals of the
order Actiniaria. They are named for the anemone, a terrestrial flower. Sea anemones are
classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia.[1] Anthozoa often
have large polyps that allow for digestion of larger prey and also lack a medusa stage.[2] As
cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra.
Metridium - Answers Phylum Cnidaria. Class Anthozoa. Subclass Hexacoralia. Order Actinaria.
Members of the genus Metridium, also known as plumose anemones, are sea anemones found
mostly in the cooler waters of the northern Pacific and Atlantic oceans. They are characterized
by their numerous threadlike tentacles extending from atop a smooth cylindrical column, and
can vary from a few centimeters in height up to one meter or more. In larger specimens, the oral
disk becomes densely curved and frilly.
Order Scleractinia - Answers Phylum Cnidaria. Class Anthozoa. Subclass Hexacoralia. True or
stony corals. Scleractinia, also called stony corals, are marine corals that generate a hard
skeleton.
Subclass Octocorallia - Answers Phylum Cnidaria. Class Anthozoa. Octocorallia (also known as
Phylum Porifera - Answers Sponges are animals of the phylum Porifera. They are multicellular
organisms that have bodies full of pores and channels allowing water to circulate through them,
consisting of jelly-like mesohyl sandwiched between two thin layers of cells
Phylum Cnidaria - Answers Jellies. Cnidaria is a phylum containing over 10,000 species of
animals found exclusively in aquatic and mostly marine environments. Their distinguishing
feature is cnidocytes, specialized cells that they use mainly for capturing prey.
Class Desmospongea - Answers The Demospongiae are the largest class in the phylum Porifera.
Their "skeletons" are made of spicules consisting of fibers of the protein spongin, the mineral
silica, or both.
Class Hexactinellida - Answers Phylum Porifera. Hexactinellid sponges are sponges with a
skeleton made of four- and/or six-pointed siliceous spicules, often referred to as glass sponges,
they are notable for their long life of 1000s of years.
Class Hydrozoa - Answers Phylum Cnidaria. Hydrozoans or "water animals". They are very small
predatory animals that can be either marine or freshwater, but mostly saltwater. There are about
3200 species belonging to the taxonomic class, which is fairly large. Some examples of
hydrozoans are the freshwater jelly (Craspedacusta sowerbyi), freshwater polyps (Hydra),
Obelia, Portuguese man o' war (Physalia physalis), chondrophores (Porpitidae), "air fern"
(Sertularia argenta), and pink-hearted hydroids (Tubularia).
Order Hydroida - Answers Phylum Cnidaria. Class Hydrozoa. an order of Hydrozoa comprising
forms alternating a well-developed asexual polyp generation with a generation of free medusae
or of abortive medusoid reproductive structures on the polyps — see leptomedusae
Order Chondrophora - Answers Phylum Cnidaria. Class Hydrozoa. They all live at the surface of
the open ocean, and are colonies of carnivorous, free-floating hydroids whose role in the
plankton community is similar to that of pelagic jellyfish. The chondrophores look like a single
organism but are actually colonial animals, made up of orderly cooperatives of polyps living
under specialized sail-structures.
Order Siphonophora - Answers Phylum Cnidaria. Class Hydrozoa. Although a siphonophore
appears to be a single organism, each specimen is actually a colony composed of many
individual animals. Most colonies are long, thin, transparent pelagic floaters. Some
siphonophores superficially resemble jellyfish. The best known species is the dangerous
Portuguese man o' war (Physalia physalis). With a body length of 40-50 m (130-160 ft), another
species of siphonophore, Praya dubia, is one of the longest animals in the world.
Order Milleporina - Answers Fire corals are colonial marine organisms that look rather like real
coral. Technically they are not corals, since they are more closely related to Hydra and other
hydrozoans. They are members of the phylum Cnidaria, class Hydrozoa, order Capitata, family
, Milleporidae. --- The very small nematocysts on fire corals contain tentacles that protrude from
numerous surface pores (similar to jellyfish stings). In addition, fire corals have a sharp,
calcified external skeleton that can scrape the skin.
Class Scyphozoa - Answers The Scyphozoa are a class within the phylum Cnidaria, sometimes
referred to as the "true jellyfish". The class name Scyphozoa comes from the Greek word
skyphos (σκύφος), denoting a kind of drinking cup and alluding to the cup shape of the
organism.
Class Anthozoa - Answers Corals. Anthozoa is a class within the phylum Cnidaria. Unlike other
cnidarians, anthozoans do not have a medusa stage in their development. Instead, they release
sperm and eggs that form a planula, which attaches to some substrate on which the cnidarian
grows. Some anthozoans can also reproduce asexually through budding. More than 6,100
species have been described.[1]
Subclass Hexacorallia - Answers Hexacorallia is a subclass of Anthozoa comprising
approximately 4,300 species of aquatic organisms formed of colonial polyps generally with 6-
fold symmetry. This includes all of the stony corals, which are vital for coral reef formation, as
well as all sea anemones, tube anemones, and zoanthids, ranged within six extant orders.[1] The
hexacorallia are distinguished from the other subclass of Anthozoa, Octocorallia, in having six
or fewer axes of symmetry in their body structure and only single rows of tentacles. These
organisms are formed of individual soft polyps which in some species live in colonies and can
secrete a calcite skeleton. As with all Cnidarians, these organisms have a complex life cycle
including a motile planktonic phase and a later characteristic sessile phase. Hexacorallia also
include the significant extinct orders of the rugose corals and tabulate corals
Order Actinaria - Answers Sea anemones are a group of water-dwelling, predatory animals of the
order Actiniaria. They are named for the anemone, a terrestrial flower. Sea anemones are
classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia.[1] Anthozoa often
have large polyps that allow for digestion of larger prey and also lack a medusa stage.[2] As
cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra.
Metridium - Answers Phylum Cnidaria. Class Anthozoa. Subclass Hexacoralia. Order Actinaria.
Members of the genus Metridium, also known as plumose anemones, are sea anemones found
mostly in the cooler waters of the northern Pacific and Atlantic oceans. They are characterized
by their numerous threadlike tentacles extending from atop a smooth cylindrical column, and
can vary from a few centimeters in height up to one meter or more. In larger specimens, the oral
disk becomes densely curved and frilly.
Order Scleractinia - Answers Phylum Cnidaria. Class Anthozoa. Subclass Hexacoralia. True or
stony corals. Scleractinia, also called stony corals, are marine corals that generate a hard
skeleton.
Subclass Octocorallia - Answers Phylum Cnidaria. Class Anthozoa. Octocorallia (also known as
