BIO 2135 Lecture Notes - Ventral Nerve Cord, Symmetry In Biology, Germ Layer
17 Jul 2014
School
Department
Course
Professor
Document Summary
Prosotomia & deuterostomes: protostomes: phyla that share the folowing characteristics, blastopore is mouth the blastocoel create endoderm (second germ layer) (diplo) Blastulation: one layer present (blastule, blastoderm) cavity around it is. Gastrulation: blastula is converted into a gastrula, blastopore forms to. Single layer pinches in (becomes endoderm surrounded by ecctoderm) Origins of mesoderm: splits off walls of primitive gut and forms guts on either side, fills space. *egg cell stages not associated with blastopore formation. Platyheliminthes (autapomorphy: incomplete gut organ, complex organ systems with branched digestive tract. Diverticulum: hollow branch or pouch that extends from the side of an. Pharynx: region of the digestive tract between the mouth and esophagus. Tissues adjacent to nutrient source (don"t need circulatory system) Tissues are adjacent to the outside of gastro: complex reproductive system associated with hermaphrodism, hemaphroditic (monoeicious) for sexual reproduction) Issue: don"t want self fertilization, lose the advantage of meiosis (variation.
