Lab 8 Flashcards
Animals in the phylum Porifera are commonly kown as
sponges
Because of their structural simplicity,sponges are said to exhibit a ____
cellular level of organization
Animals in phylum Cnidaria exhibit ____ because they have muscles and nerves but lack organs
tissue-level organization
Two features unique to Cnidarians is that they have ____ symmetry and they are ____ which mans they have two germ layers
radial
diploblastic
Describes animals in which three germ layers are produced in embryonic development
Triploblastic
Ectoderm and endoderm are produced during embryonic development
Diploblastic
Sessile organisms that attach themselves to rocks and other substrates with their sac-like body supported by water
Sponges
Sponges support comes from a skeleton made of inorganic ___ or i some cases interconnecting collagen fibers known as _____
spicules
spongin
The name __ refers to the fact that a sponge’s body is little more that a sac perforated by numerous pores and chambers through which a steady flow of water is passed into the body.
Porifera
A epithelial layer forms the outer wall Pores are formed by porocytes that extend through the unfolded body wall.
Simple Sponge
Cells with a flagellum surrounded by a collar of microvilli that traps food particles. Called ____ circulate water and filter microscopically small food particles.
choanocytes
Sponges have a ____ fo attachment and an opening called a ____ surrounded by long spicules
Basal end
osculum
On a cross section of a simple sponge Grantia the opening which runs the entire length down the center of the sponge is the __.
spogocoel
The pores ____ that allow water to enter _____ of a ponge
dermal ostia
incurrent canals
Adjacent to each incurrent canal of a sponge is a ____ separated by a layer of cells
radial canal
In sponges water passes through a layer of cells by way of special cells called
porocytes
Radial canals are lined by flagellated cells called
choanocytes
Inside a sponge the remaining water and indigestible materials pass along the radial canals to the spongocoel and then out through the
osculum
What is the flow of water through a sponge ?
Dermal ostium Incurrent canals Porocyte Radial canals Choanocytes Amoebocyte Spongocoel Ostium
The simplest body plan of sponges is known as ____. Small tube shaped, and have a limited internal surface area over which to filter food
asconoid
Some sponges have overcome size limitation by the evolution of folds in their body walls
Syconoid
Sponges which represent the majority of the species, exhibit even more folding including a complex labyrinth of internal chambers
Leuconoid
The classification of sponges is based on the
shape and composition of their spicules
The only class of sponge with spicules composed of calcium carbonate. Spicules are needle-shaped with three or four prongs. Sponges in this class are typically small and include the three levels of body complexity. These sponges are found in shallow coastal waters.
Class Calcarea
These sponges have six-rayed spicules made from silica, they are more symmetrical and can be shaped like a cup or urn. Their body structure is syconoid or leuconoid but never asconoid. This sponge is where young male and female shrimp often live
Class Hexactinellida
This class of sponge includes 95% of all sponge species. All are leuconoid. Their skeletons consist of spongin fibers, siliceous spicules or a combo of both. Spicules are never 6 rayed. This class includes the “bath” sponge
Class Demospongiae
Some sponges are ___ which means they produce both male and female gametes
Hermaphroditic
Asexual reproduction of sponges consists of _____ or the release of ____ in the autumn
budding
gemmules
Aggregates of amoebocytes covered by a hard spongin-like material and covered with spicules
Gemmules
With the onset of winter parent sponges will ___ but their gemmules can withstand freezing and develop into mature sponges in the following spring
disintegrate
In Cnidarians the central point is a mouth that extends into the _____
gastrovascular cavity
These animals lack an anus and surrounding the central mouth are tentacles lined with stinging cells called cnidocytes
Cnidaria
Stinging cells called cnidocytes contain small barbed structures called ___ that are coiled threads that can be discharged like tiny harpoons
nematocycts
The body wall of Cnidarians consists of two layers of cells an outer _____ for protections and an inner ___ for digestion.. Between these two layers is a jelly-like ___ which is particularly thick in jellyfish
epidermis
gastrodermis
mesoglea
Cnidarians as a group have two basic body forms the sessile ____ and he free-swimming ____
polyp
medusa
Cnidarians that adhere to a substrate by their aboral surface with mouth and tentacles extended for feeding
POlyps
Cnidarians that are free-swimming and disc or umbrella-shaped with mouth and tentacles on the lower surface
Medusa
Many Cnidarians alternate between the two forms polyp and medusa and are called
Polymorphic
This class includes hydras and Obelia. The polyp is the predominant form but most have a medusa stage as well.
Class Hydrozoa
Commonly referred to as jellyfish, have a life cycle that emphasizes medusa over polyps
Class Scyphozoa
Represented by sea-anemones and corals, express only the poly form
Class Anthozoa
Commonly found in shallow freshwater ponds. Use their stinging cnidocytes o capture small invertebrate prey. Lack a medusa stage.
Phylum Cnidarian
Class Hydrozoa
Hydra
A colonial form found in shallow marine waters attached to substrates such as seaweed or rocks. Alternates between medusa and polyp form. The medusa is the sexual stage. Has two types of polyps; feeding polyps and reproductive polyps
Phylum Cnidarian
Class Hydrozoa
Obelia
Feeding polyps are called ____ and reproductive polyps are called ____
gastrozooids
gonozooids
Commonly known as the Portuguese Man-of-War, resembles a jellyfish but is actually a floating colony of highly integrated polymorphic polyps and medusoids. SOme form a gas-filled sac and others have long tentacles. Tentacles are armed with a battery of cnidocytes.
Phylum Cnidaria
Class Hydrozoa
Physalia
The gas-filled chamber of the Portuguese Man-of-War is called a
pneumatophore
True jellyfish. The medusa stage dominates. Are mostly free swimming marine organisms.
Phylum Cnidaria
Class Scyphozoa
In class Scyphozoa food is swept up to the mouth by ciliated ____ After the food is digested in the gastrovascular cavity, nutrients are transported around the body via a system of _____ and the ___.
oral arms
radial canals
circular canal
If you look closely at the tentacles fringing Aurelia’s body you will notice 8 small gaps in the tentacles. Each gap contains a ___ which is sensitive to light, chemicals, and body position
Sense organs
Solitary (sea anemones) or modularly colonial (corals) marine organisms. Non-polymorphic exhibit only the polyp form. May or may not secrete an external supporting calyx of calcium carbonate in which they are embedded.
Phylum Cnidaria
Class Anthozoa
