Biology Study Guide Uses of Sponges-possess no symmetry and take on a variety of shapes. They’ve got 2 layers of cells that are separated by a thin, Jellylike substance. Outer layer-epidermis, and Jellylike substance-mesenchyme. Morphology of Molluscs-they have a soft body they are more fragile. They also have more difficulty to support their bodies in terrestrial environments or to fixate to substrates in aquatic habitats. Many species solve these problems by secreting a calcareous carapace, or shell, an exoskeleton to upport and protect them and to prevent dehydration.
Platy Hemises- commonly called flatworm. have no body cavity other than the gut, same pharyngeal opening both takes in food and expels waste. Lack of a cavity also constrains flatworms to be flat. Earthworm-segmented worm. they inhabit every bit of moist soil in the world. they possess bilateral symmetry and are made up of segments that look like little rings stacked next to each other. Earthworm Reproduction-simultaneous hermaphrodites, meaning worms have both male and female reproductive organs.
Planaria Reproduction-hermaphroditic-possess both male and female sex glands. planarian cannot fertilize its own eggs; eggs must be fertilized by sperm of another planarian. In another method of reproduction, a planarian constricts behind the pharynx and separates itself into two pieces ; then, both pieces grow back their missing parts and become two new planarians. Vocab: 1) Budding-form of sexual reproduction. Its when a yeast buds, the nucleus of the cell reproduces inside a single cell.
A section of the cell wall and plasma membrane then well to form a pouch into which the nucleus and some cytoplasm flow. 5) Gizzard- the hind part of the stomach, especially modified for grinding food. (mostly on birds) 6) Nephridia-small organs. they function like your kidneys, are in every segment of the earthworm’s body except the 1st 3 and the very last one. 8) Pharynx-it ingests soil through it mouth by using it as a vacuum to suck. Diagrams: The Life Cycle of a Jellyfish Basic Anatomy of a Common Earthworm Structure of a Sponge Biology Module 2: Study Guide By morgannf95