Principles of Biology (Biol 198) Robbie Bear KSU Exam 7 with Verified Solutions

Principles of Biology (Biol 198) Robbie Bear KSU Exam 7 with Verified Solutions _____ is a type of connective tissue and _____ is a type of epithelial tissue. Bone; lining of the digestive tract What is the top side of a vertebrate and other bilateral organisms? Dorsal side What is the bottom side of a vertebrate and other bilateral organisms? Ventral side Germ layer on the outside layer of the body. Forms skin and nervous system (nerves). Ectoderm The middle germ layer. Mostly muscle and bones. Mesoderm The inner germ layer. Forms intestines and other internal organs. Endoderm Some animals only have two germ layers. Which one is missing? Mesoderm What type of organism do you predict would lack a mesodermal layer? Aquatic invertebrates such as Cnidaria (jellyfish) and Ctenophora. How many germ levels do organ level organisms have? What are some examples of organ level organisms? 3 germ levels. Everything except for Cnidaria and Porifera. Humans, birds, fish, many many more. How many germ levels do tissue level organisms have? What are some examples of tissue level organisms? 2 germ levels. Cnidaria (jellyfish) How many germ levels do cellular level organisms have? What are some examples of cellular level organisms? ZERO germ levels. Porifera Fluid-filled space around internal organs. Body cavity Internal body cavity lined with cells derived from the mesoderm. Coelom Fluid-filled cavity is present, but only the outside is lined with mesoderm and organs are not completely anchored. Pseudocoelom What are 6 advantages to having a coelom? 1. Internal organs can be held in place with connective tissue (mesenteries). 2. Further specialization and complexity of organs is possible. 3. Independent movement of internal organs and body wall is possible. Ex: digestive wall can be more muscular without displacing other organs. 4. Internal fluid can protect the internal environment and aid in movement of materials. 5. A fluid-filled cavity can function as a "hydrostatic skeleton," where the animal can move by exerting hydraulic pressure on the fluid in the coelom. 6. Overall, coelems allowed animals to evolve more complex internal structure and to be more flexible in their movement. What is meant by the term "segmented body?" Body is divided into repeating units. What is an advantage of a segmented body? There is more independent movement of body parts and more specialization of body parts. What is cephalization? Development of a structure at one end of the body with specialized feeding and sensory structures (head).