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Unit 2 Guided Notes

Kingdom Animals, Phyla Porifera, Cnidaria, & Ctenophora … Guided Notes
All members of Kingdom Animalia (aka Metazoa) share five very basic characteristics:
They are ____________________ - cells with a nucleus & membrane-bound organelles.
They are ____________________ - cells are somewhat to very specialized; most form tissues.
They are ____________________ and ____________________ - Animals ingest then digest.
Reproduction is usually ________________ (though some reproduce asexually as well) – which
increases variation within the species and enhances evolution.
All animals are grouped into two main categories:
_____________________________ lack backbones and other interior frameworks.
_____________________________ have backbones and other parts of an interior framework
called an ________________________.
3. The general form an organism takes is its ________________, and there are four main types:
If there is no special form or shape, the animal shows ____________________, as in sponges.
__________________ symmetry is ball-shaped and meets the environments equally on all sides,
making this the perfect symmetry for floating organisms like the protozoan Volvox.
_______________ symmetry has two ends but no right or left side. It is cylindrical and is
common to animals that move little, like the sea jellies in the plankton and the echinoderms in the
___________________ symmetry has two sides that are similar in shape and form, as seen in
worms, arthropods, and vertebrates.
4. Phylum ________________ encompasses the sponges. The name comes from the Latin __________,
meaning “pore” + __________, meaning “to bear.”
5. Sponges have these characteristics:
The body is filled with ____________.
The organism is ______________ - lives attached.
The size ranges from _____ to over ____ feet.
Habitat: all are ______________; most are ____________.
Sponges are subdivided into classes based on ________________________________________
6. ________________ are support structures
unique to sponges and are made of three main
materials: __________________________
7. The classes of sponges are
Spicule composition
8. Sponges show a low degree of cell specialization – the lowest of all animals – but there are specialized
cells within the sponge body:
The _____________________ is also called the
collar cell. It circulates water and gathers food.
They are found at the center of every pore the
enters the sponge body.
The ____________________ is also called the
epidermal cell. These cells cover the entire body
of the sponge. Many secrete special defensive
chemicals and so are under investigation as a
possible source of pharmaceuticals.
The ____________________ is also called the
mesoglea. It is not composed of cells but rather
is a jelly-like substance located between the inner
and outer layer of cells.
___________________ are irregularly shaped
cells located in the mesenchyme, where they act
as transporters of food, waste, sperm, and eggs.
The ________________ is a tubular cell through
which water enters the central cavity, called the
9. The large excurrent pore through which water leaves the sponge body is called the
_______________. Water enters through __________________ pores.
10. Sponges are such simple animals that they can reproduce both sexually and asexually.
In sexual reproduction, ____________ are released into the water. Spawning is triggered by the
__________________ of neighbors. _______________________ gather the sperm and
____________________ deliver them to the eggs, where fertilization occurs, producing a
______________ that develops into a __________, which then exits through the collar cells and
enters the ________________ until mature enough to “settle down.” Because they naturally
contain the organs of both sexes, we describe sponges as __________________________, few
of which self-fertilize.
Asexual reproduction may occur in one of two ways:
__________________________ occurs when sponges regrow lost or damaged parts.
__________________ occurs when a new organism grows from the original.
Sponges are so primitive, that a living sponge can be “blended” then placed back into still water, and
the animal will reassemble itself.
11. Phylum ____________________ aka Coelenterata includes the jellyfish, corals, hydras, sea anemones,
and their relatives:
In size the range from ___ to ______ feet.
Their habitats are all ______________,
mostly _____________ - salt water.
Symmetry is ____________.
__________________ have special
stinging cells.
There is a gut with ___ opening.
There is no ____________________.
12. Cnidarians are divided into classes based on the dominant body form in their life cycle:
The ____________ is sessile – lives attached
to a substrate.
The ____________ is a free-swimming “bell.”
Polyps may “bud off” to form medusas.
13. The classes of cnidarians are
Dominant form
14. Tentacles may look both beautiful and delicate, but they hold
special stinging cells called __________________________
that are used for both offense (getting food) and defense.
There is a trigger that sets it off, a barbed, hollow filament,
and a venom gland in each nematocyst.
15. The most toxic animal in the ocean is the ________________, found off the coast of Australia in the
Indian Ocean.
16. Many anthozoans for special partnerships = SYMBIOSIS – with other organisms.
Hard corals cannot live without their algal partners, the __________________________.
(mutualism) In ______________________________ the coral polyp expels its algal partners.
The coral skeleton/polyps lose their color and the coral dies.
Sea anemones are home to a variety of animals, including “Nemo” - ____________________.
17. Like sponges, cnidarians reproduce both sexually and asexually, producing some life cycles that are
extremely complicated!
All cnidarians go through a larval stage called the
________________, which they share with the
flatworms. It consists of a flattened, bilateral
body covered with cilia.
Cnidarians also go through a stage called
the ____________ larva that precedes
the medusa stage. This larval form can
either grow into a mature, sexual medusa
or settle down to form a polyp.
18. Phylum _________________ encompasses the so-called “comb jellies.”
The name comes from the Greek ____________
= “comb” + ____________ = “bearing.”
In size they range from ____ inch to ____ feet.
Without exception, ctenophores are ____________.
They are often ____________________________,
giving off “living light” as phosphorus compounds
interact with oxygen.
They have ____ ciliated bands.
They have ____ tentacles (no stinging cells).
They have a gut with ____ opening.
They lack a ____________________.
They show ________________ symmetry.
Examples include the sea walnut and Beroe.