Biology Quiz On Animal Phylum Cnidaria

A blind end cavity that functions in digestion, gas exchange, metabolic waste removal, discharge of gametes, and consists of a single opening is called a gastrovascular cavity. This type of cavity is commonly found in organisms such as cnidarians, flatworms, and some other invertebrates. It allows for the intake of food, digestion, and absorption of nutrients, as well as the elimination of waste products. Additionally, it plays a role in gas exchange and the release of reproductive cells.

Cnidocytes are specialized cells found in certain animals, such as jellyfish and sea anemones, that contain nematocysts. Nematocysts are stinging structures used for defense and capturing prey. These cells are unique to cnidarians and are essential for their survival and feeding strategies.

The medusa life cycle is sexual, and a free swimming life form. Unlike polyps, which are typically attached to a substrate, medusas are free-floating organisms that reproduce sexually. Sea anemones are polyps, not medusas, and they reproduce asexually. Jellyfish, on the other hand, refer to the medusa stage of the life cycle, not the entire life cycle itself. Therefore, the correct answer is medusa.

Dioecious refers to a reproductive system where an organism has separate male and female individuals. In sexual reproduction, this means that male and female individuals are required for fertilization to occur. This is in contrast to monoecious, where both male and female reproductive organs are present in the same individual, and self-fertilizing, where an organism can fertilize its own eggs with its own sperm. Therefore, the correct answer is Dioecious.

Nematocysts are specialized cells found in cnidarians like jellyfish and sea anemones that contain venomous harpoons used for defense and capturing prey. Once a nematocyst is discharged, it cannot be reused and must be replaced by the organism. Therefore, the statement that nematocysts can be reused is false.

The correct answer is gastrodermis. The gastrovascular cavity is a central cavity found in certain animals, such as cnidarians and flatworms, that functions in both digestion and circulation. The gastrodermis is the inner lining of this cavity and is responsible for the secretion of digestive enzymes and absorption of nutrients. It also helps in the distribution of nutrients and gases throughout the body.

Gonangia are reproductive structures found in certain colonial hydroids (a type of cnidarian). They produce medusae, which are the free-swimming, sexual stage in the life cycle of these organisms. Medusae release gametes into the water, leading to the formation of new hydroids.

Nerve net cells conduct bidirectionally means that they can transmit signals in both directions along their network. This suggests that the nerve net cells have the ability to send and receive information from multiple sources, allowing for communication and coordination between different parts of the nervous system. This bidirectional conduction is crucial for the functioning of the nervous system, as it enables the integration and processing of sensory information, as well as the coordination of motor responses.

Species in the phylum Cnidaria have a diploblastic tissue level of organization, meaning they have two germ layers: the ectoderm and endoderm. They also have a gastrovascular cavity, which functions in both digestion and circulation. Cnidarians exhibit radial symmetry, meaning their body parts are arranged around a central axis. They possess cnidocytes with nematocysts, specialized stinging cells used for capturing prey and defense.

Cnidarians, such as jellyfish and corals, have a hydrostatic skeleton, which means their body structure is supported by the pressure of the fluid (water) inside their body. This hydrostatic skeleton allows them to maintain their shape and move through the water. The buoyancy of water also helps support their body by counteracting the force of gravity, allowing them to float and maintain their position in the water column.

Cnidarians have a two-part life cycle that includes two distinct body forms: the medusa and the polyp. The medusa form is typically free-swimming and has a bell-shaped body with tentacles hanging down, while the polyp form is usually attached to a substrate and has a cylindrical body with tentacles facing upwards. This two-part life cycle allows cnidarians to adapt to different environments and maximize their chances of survival and reproduction.

After catching its prey, the organism performs extracellular digestion in the cavity. This means that the digestion process occurs outside the cells, where the prey is broken down into smaller molecules. Once the prey is digested, the resulting materials are absorbed intracellularly, meaning they are taken up by the cells and used for various metabolic processes.

The GVC, or Gastrovascular Cavity, is a structure found in certain organisms like jellyfish and flatworms. This structure allows these organisms to contain and digest large prey items within their bodies. By being able to consume a variety of prey, these organisms can obtain a diverse range of nutrients, leading to greater energy availability. This energy can then be used to support more complex physiological processes, such as growth, development, and reproduction. Therefore, the GVC plays a crucial role in facilitating variety, energy, complexity, and reproduction in these organisms.

Food is mostly captured by cnidocytes on the tentacles. Cnidocytes are specialized cells found in the tentacles of certain organisms, such as jellyfish and sea anemones. These cells contain nematocysts, which are stinging structures used to capture prey. Zooplankton refers to small organisms that drift in the water and serve as a primary food source for many marine animals. Therefore, the correct answer is zooplankton, cnidocytes, as cnidocytes on the tentacles capture zooplankton for food.

The two tissue types mentioned in the question are gastrodermis and epidermis. These two tissues are separated by mesoglea. Gastrodermis is the inner layer of tissue that lines the digestive cavity, while epidermis is the outer layer of tissue that covers the surface of the organism. Mesoglea is a gelatinous layer that lies between the gastrodermis and epidermis, providing support and structure.