Quiz 3 Flashcards
What is Hydra Vulgaris?
A freshwater cnidarian known for its regenerative properties and relevance in studies of tissue differentiation and cellular processes.
Hydra Vulgaris is utilized in research due to its ability to regenerate from small tissue fragments.
Why is Hydra Vulgaris significant in scientific research?
It contributes to studies in regeneration, developmental biology, aging, and human health.
Its regenerative abilities provide insights into cellular health and aging, which parallels human biology.
What are the major germ layers in embryonic development?
Ectoderm, endoderm, and mesoderm.
These layers give rise to various tissues and organs in animals.
Define cephalization.
The concentration of sensory organs and nervous system components in the head region.
This process is significant in the evolution of complex animal forms.
What is the spongocoel?
The central cavity in sponges where water flows in.
It plays a crucial role in the sponge’s feeding and respiratory processes.
What are the three types of sponge body forms?
Asconoid, syconoid, and leuconoid.
Each type varies in complexity and structure.
What is mesoglea?
A jelly-like layer found between the epidermis and gastrodermis in cnidarians.
This layer provides support and buoyancy to the organism.
Fill in the blank: The process where the blastula reorganizes into two layers of gastrula is called _______.
gastrulation
What is a planula?
A ciliated form of cnidarians.
It is an early larval stage in the life cycle of cnidarians.
True or False: Hydra is a solitary species.
True
While some cnidarians are colonial, Hydra typically exists as a solitary organism.
What characterizes the Hydrozoa clade?
Includes solitary and colonial species like Hydra and Obelia.
This clade exhibits diverse forms and life cycles.
What type of spicules do Hexactinellida sponges have?
Six-pointed (triaxon) silica spicules.
These sponges are also referred to as glass sponges.
What is a gemmule?
A survival structure in sponges, often clustered within a spicule shell.
Gemmules are important for asexual reproduction and survival in harsh conditions.
What does the term ‘strobila’ refer to in cnidarians?
A stage in the life cycle where the polyp produces free-swimming medusae.
This is part of the asexual reproduction process in certain cnidarians.
What is the significance of the clade Anthozoa?
Includes sea anemones and corals, exhibiting radial symmetry and small polyps.
This clade plays a crucial role in marine ecosystems.
What is the primary function of the digestive system that originates from the endoderm germ layer?
It evolved from no digestive system to a complete digestive system in animals.
This evolution reflects the complexity of animal anatomy and physiology.
List the three clades of Phylum Cnidaria mentioned.
- Hydrozoa
- Scyphozoa
- Anthozoa
Each clade contains distinct organisms with unique characteristics.
The Animalia (Metazoa) clade
division of the Opisthokonta. Animals are a
monophyletic group of multicellular, aerobic, diploid, heterotrophic organisms
Level of organization
cellular –> tissue –> organ –> organ system.
evolution cells organized into tissue layers
first two (diploblastic)
then three layers (triploblastic)
Animals at the next level of evolution (diploblastic) have how many germ layers
2 endoderm and ectoderm
How many germ layers do triploblastic have
All 3
Ectoderm
Forms skin and nervous tissue
Endoderm
Forms digestive and respiratory systems
Mesoderm
Forms bone muscles and blood
Cnidaria are
Diploblastic
The bilateria are
Triploblastic
Incomplete digestive system
Mouth only
Complete digestive system
Mouth and anus
Animals that have no cavity around their organs
Acoelomate
Animals that have body cavity surrounded with mesoderm
Coelomate
Sessile
Immobile, sponged but have motile larvae
Sponges are
mostly asymmetrical
no germ layers, no body cavity
several types of cells:
o an outer layer of “epidermal” cells for protection
o an inner layer of choanocytes (collar cells) used to create a current for
feeding.
o Between these two layers are amoebocytes
Spicules and spongin are the structural support of
Sponges
a unique characteristic of the Porifera
Spicules or demospongin as suppor
Asconoid sponges
e simplest sponge body form. It consists of an outer
layer of epidermal cells and an inner layer of choanocytes with amoebocytes
sandwiched in between
Syconoid body forms
side walls that have wave-like folds forming
incurrent and radial canals, but a single spongocoel and osculum. Scypha
(Grantia) is a syconoid sponge.
Leuconoid sponges have
complex system of chambers lined with collar cells,
and canals that empty into an osculum. Typical bath sponges are leuconoid
sponges that often have many oscula.
Calcarea
spicules made of calcium carbonate (CaCO3.). All three body forms
are found in this group. Scypha (Grantia) is a syconoid sponge in the Calcarea
Hexactinellida, or “glass sponges,
lacy skeleton out of 6-pointed (triaxon)
silicon spicules
Flagellated choanocytes provide the glass sponge what
supply the sponge with food and aeration. This sponge form a mutualistic relationship with spongicola shrimp. A pair of shrimp enter the sponge when they are larvae.
Demospongia contains
vast majority of sponges including many freshwater and
commercial marine sponges.
spongin,
silica spicules, a network of protein fibers
Cnidaria have
They also have stinging cells called nematocysts in their tentacles and a nerve
net that weaves through the epidermal layer
Eumetazoa embryonic development
zygote divides mitotically into a solid ball of cells (cleavage stages.) That ball of
cells hollows out into a blastula. One side of the blastula rolls in to form a two-layered
gastrula with an outer ectoderm, an inner endoderm, and an opening into the open gut
called the blastopore.
Cnidarians have 2 tissue layers
an epidermis and a gastrodermis
A mouth forms from the
Blastopore
The Anthozoa “Class-level” Clade
Anthozoans are large-bodied polyps. There is no medusa stage. Corals, sea fans, and sea
anemones are anthozoans
Scyphozoans
Truejellyfish
Obelia
colonial hydrozoan. Many feeding polyps exist on one branching organism.
There are also reproductive polyps that produce tiny medusae by asexual means.
Hydrozoa “Class-level” Clade
small, slender polyp or medusa body form Portuguese man of war
protostomes, the blastopore becomes
the mouth at the anterior end
deuterostomes, the anus forms in
the region of the blastopore at the posterior
end
The Protostomia can be divided into two subgroups
Lophotrochozoa and the
Ecdysozoa.
The Lophotrochozoa have either
either trochophore larvae or ciliated structures
around the mouth called lophophores
Ecdysozoans shed their
outside cuticle or shell.
Annelids are the
Segmented worms
Annelid characteristics are
Triploblastic
Organ system level of organization
Bilateral symmetry
Coelomate – true coelom body cavity bounded by mesoderm on all sides
Complete digestive system with a mouth and anus
Cephalization
Segmentation – repeating body parts allowing specialization
Possess a closed circulatory system
Setae, paired bristle-like appendages made of chitin, are found in most annelids
The Oligochaete “Subclass” has
as few setae and
includes the earthworm.
The Polychaete “Class” has
as many setae and includes the marine
worms.
The Hirudinea “Subclass,” the leeches, are
re highly specialized and have no seta
The clitellum is used in
Mating
What is the Longfin Inshore Squid used for in research?
The Longfin Inshore Squid is a model organism particularly used for neuroscience research due to its large axons.
What significant discoveries have been made using the Longfin Inshore Squid?
Discoveries about nerve cell function, synaptic transmission, and neuronal signaling similar to human biology.
