Sponges, Cnidarians & Worms

Life Science - Middle School

1
/
2
medusa planula larva polyp polyp planarian tapeworm roundworm ephyra budding polyp Body Plans polyp medusa central cavity central cavity mouth mouth Sponges Sponges are the simplest of all animals belonging to the phylum Porifera. In fact, for a long time people thought that sponges were plants. Like plants, mature sponges remain in one place for the rest of their life cycle, attached to rocks underwater. How does a sponge reproduce? Sponges can reproduce both sexually and asexually. When a sponge reproduces asexually, it uses a process known as budding. A sponge is neither a male nor a female, but it is capable of producing both egg and sperm cells but never at the same time. Body Structure oscula central cavity After fertilization, an immature form of a sponge develops known as a larva. 3. The sperm enters another sponge through a pore and fertilizes an egg. 2. The larva is carried away by water currents. 4. 2. 4. 3. 5. 1. 6. An adult sponge produces sperm cells. 1. 5. The larva attaches itself to a rock or other hard surface and remains there for the rest of its life cycle. Cnidarians Cnidarians are invertebrate animals that have stinging cells to capture food and defend themselves. Examples of cnidarians include jellyfishes, hydra, sea anemones and corals. Body Structure Cnidarians have two body forms, the vase-shaped polyp and the bowl-shaped medusa. While polyps reproduce asexually by budding, medusas reproduce sexually. Life cycle of a Jellyfish A jellyfish has a life cycle that includes both a polyp and a medusa. Sperm and egg cells are released. The egg cell is fertilized by a sperm cell. A larva develops. The larva develops into a polyp. The polyp reproduces asexually releasing many disc-shaped structures. Each disc-shaped structure develops into an adult medusa. larva larva adult sponge sperm cells egg Spike Spikes give the sponge its shape and allow it to stay upright. They also provide the sponge protection from predators. Pore A sponge has many holes in its body called pores that allow water to pass through into the central cavity. Water leaves the sponge through the large hole on top called the oscula. Jelly-like cell Jelly-like cells are found between the spikes that digest food, remove wastes and produce egg or sperm cells. Collar cell Collar cells beat back and forth moving water through the pores trapping tiny food particles in the process. brain mouth blood vessels digestive tract nerve cord anus earthworm reproductive organs Roundworms Roundworms have bodies in the shape of a cylinder. They are the simplest organisms with a brain and can respond to light, touch and vibrations. They live freely in soil and water. Segmented worms Segmented worms have cylindrical bodies made up of many sections with grooves in between each section. Earthworms and leeches are examples of segmented worms. Flatworms Flatworms are worms that are flat. Although most flatworms are too small to be seen with the naked eye, some species can grow up to ten meters long. The tapeworm is a parasitic flatworm that depends on its host for food. Planarian is a non-parasitic flatworm that lives freely in ponds, streams and oceans. Worms Scientists classify worms into three separate groups or phyla - flatworms, roundworms, and segmented worms. intestine waste removal organs Sponges, Cnidarians & Wo rms © Copyright NewPath Learning. All Rights Reserved. 94-4707 www.newpathlearning.com
planula larva ephyra budding polyp 2. 4. 3. 5. 1. 6. 1. 2. 3. 4. 5. Sponges ________________ are the simplest of all animals belonging to the phylum Porifera. In fact, for a long time people thought that sponges were ______________. Like _____________, mature sponges remain in one place for the rest of their life cycle, attached to rocks underwater. How does a sponge reproduce? Sponges can reproduce both ________________ and ________________. When a sponge reproduces asexually, it uses a process known as ________________. A sponge is neither male nor female, but is capable of producing both ________________ and ________________ but never at the same time. Body Structure Cnidarians __________________ are invertebrate animals that have _______________ to capture food and defend themselves. Examples of cnidarians include ________________________________ ________________________________. Body Structure Cnidarians have two body forms, the vase-shaped _________________ and the bowl-shaped _________________ . While polyps reproduce asexually by _________________ , medusas reproduce sexually. Life cycle of a Jellyfish A jellyfish has a life cycle that includes both a ________________ and a _______________ . Spike _________________________ _________________________ Pores _______________________ _______________________ _______________________ Collar cell ______________________ ______________________ brain mouth blood vessels digestive tract nerve cord anus reproductive organs Roundworms _____________________________________________ _____________________________________________ Segmented worms ________________________________________ ________________________________________ ________________________________________ Flatworms ______________________________ ______________________________ ______________________________ Worms Scientists classify worms into three separate groups or phyla - ___________________, ___________________, and ____________________. intestine waste removal organs central cavity central cavity mouth mouth \|xiBAHBDy01771kzU Key Vocabulary Terms asexual reproduction planarian budding polyp central cavity pores cnidarians roundworms collar cells segmented worms egg cells sexual reproduction flatworms sperm cells jellyfish spikes larva sponges medusa stinging cells phylum tapeworms Sponges, Cnidarians & Wo rms © Copyright NewPath Learning. All Rights Reserved. 94-4707 www.newpathlearning.com