Invertebrate Zoology: Test 1 Sponges, Cnidarians And Comb Jellies

Internal buds found in freshwater sponges that result from asexual reproduction are known as gemmules. Spores, zoospores, and larvae are not the correct terms for this specific reproductive structure.

The correct term for the larva is 'amphiblastula', which is specific to sponges and their reproductive process.

Spicules are tiny, hard structures that provide support for Porifera, commonly known as sponges. They can be made of silica or calcium carbonate. Nematocysts are stinging structures found in cnidarians like jellyfish. Gastropods are a class of mollusks, and mycelium is the vegetative part of a fungus.

Choanocytes are specialized cells found in sponges that create a water current to capture and filter small food particles. Siphonocytes, Amoebocytes, and Collencytes do not perform the same function in sponges as choanocytes.

The correct body plan of a sponge described in the question is the asconoid. In the asconoid body plan, water enters through pores into a central cavity known as the spongocoel, surrounded by a single layer of choanocytes for filter feeding.

The leuconoid body form of a sponge is the most complex structure, characterized by an extensively branched canal system. Asconoid and Syconoid are simpler body forms of sponges with less complex canal systems. Diploblastic refers to organisms that have two germ layers, which is not directly related to the body form of sponges.

The correct answer is Syconoid because in this body plan, the body wall is folded to form radial canals, resembling the structure of Grantia sponges.

Euspongia bath sponges are made of spongin, which is a type of protein that gives the sponge its soft and absorbent quality. Options like Calcium carbonate, Silica, and Hyaluronic Acid are not the primary material used in Euspongia bath sponges.

In Synconoid sponges, water enters through prosoplye into the flagellated chamber, exits through apopyle, and finally exits through the osculum. The incorrect answers provide alternative pathways in other types of sponges or incorrect sequences within Synconoid sponges.

Parazoa refers to a group of organisms that are primarily multicellular but lack true tissues, meaning they have differentiated cells but do not form organized tissue structures like other animals.

Sponges can reproduce asexually through gemmules, which are internal buds, and budding, where new organisms grow from the parent sponge. The incorrect answers do not correspond to the asexual reproduction methods used by sponges.

Hydra and Obelia are commonly known hydrozoans, while jellyfish, sea anemones, and coral belong to different groups of cnidarians.

Scyphozoans are exclusively marine organisms that use nematocysts to capture prey.

In cnidarian life cycle, the asexual polyp phase involves a tubular body with a mouth surrounded by tentacles, while the sexual medusa phase involves a bell-shaped body with tentacles. Anthozoans, a class of cnidarians, do not have a medusa phase in their life cycle.

A zooid is specifically a distinct individual forming part of a colonial animal structure, such as found in bryozoans or hydrozoans. It is not a fish, plant cell, or land-dwelling reptile.

Cnidarians are a group of invertebrates that include jellyfish, corals, and sea anemones. Chondrophores are a type of colonial cnidarian known for their skeletal structure.

A siphonophore is a colonial organism belonging to the phylum Cnidaria, whereas corals, jellyfish, and anemones are also cnidarians but not specifically colonial like the siphonophore.

Anthozoans are a specific group of marine animals that include anemones, corals, sea pens, sea whips, and sea fans. They do not have a medusa stage in their lifecycle. The word root 'antho' means flower, and 'zoan' means animal, combining to form 'flower animal'. This distinguishes them from other groups of animals with different characteristics and stages in their lifecycle.

The key difference between Scleractinians and Actinarians lies in their ability to build reefs due to the presence of CaCO3 in Scleractinians and its absence in Actinarians.

Corals and zooxanthellae have a mutualistic relationship where both organisms benefit from each other's presence. The dinoflagellates (zooxanthellae) living within the coral tissues perform photosynthesis, providing oxygen and nutrients to the coral. In return, the coral offers a protected environment for the zooxanthellae and supplies waste nutrients needed for photosynthesis.

Ctenophores are unique in their method of capturing prey using colloblasts instead of nematocysts found in cnidarians. Additionally, cnidarians typically have radial symmetry while ctenophores exhibit bilateral symmetry.

The manubrium canal is a structure found in the foot of a jellyfish (Scyphozoa) and is responsible for transporting food to the stomach. The other options provided are incorrect as they do not correctly identify the tube situated in the foot of a jellyfish.

True Jellyfish belong to the class Scyphozoa, which are known for their iconic bell-shaped body and stinging tentacles. Anthozoa, Hydrozoa, and Cubozoa are other classes of cnidarians, but they do not include True Jellyfish.

The correct life-cycle of Aurelia involves several distinct stages of development from amphiblastula to medusa, including planula, scyphistoma, strobila, and ephyra. The incorrect answers provided do not accurately depict the complete life-cycle process of the 'moon jelly'.

Mesoglea is the gelatinous material that acts as structural support in jellyfish (Scyphozoa) and comb jellies (Ctenophora). It lies between the outer epidermal layer and the inner gastrodermis.

Rhopalia are small sensory structures found in Scyphozoa that contain photoreceptors, balance organs, and possibly chemoreceptors. They are responsible for detecting light, gravity, and chemicals in the environment.