Exam # 3 Study Guide (Selected Answers) PDF

Chapter 32 1. What makes an organism an animal? heterotroph, multicellular no cell wall, cells are connected via fibers (connected tissue), cells organized into tissues, food processed inside the body, nerve, muscle tissue, embryonic development: morula, blastula...

Chapter 32 1. What makes an organism an animal? heterotroph, multicellular no cell wall, cells are connected via fibers (connected tissue), cells organized into tissues, food processed inside the body, nerve, muscle tissue, embryonic development: morula, blastula, gastrula, sex cells are produced right after meiosis, plants & fungi meiosis followed by mitosis and then sex cells. 2. What is the origin of multicellular animals? Choanoflagellates, sister groups to animals, a protist filter feeder, adhesion proteins (mostly found in animals) Similar to the collar cells of sponges 3. What is the importance of Hox genes in early animal evolution? Hox genes are thought to have led to the increasing complexity of the animal e.g., arthropod body plan, sgm identity, determining where limbs and how many limbs, antenna, swimming appendages, sgm will form during emb. development, along the anterior-posterior body axis The *Hox* gene family underwent a series of duplications in animals. *Hox* genes regulate the formation of the anterior-posterior axis in only bilateral animals. Produce especially many different arthropod body plan.  Pin page 4. Which characterizes an animal body plan? Symmetry, body cavity, tissues, and cleavage a. Symmetry Radial & bilateral b. Tissues Ectoderm, endoderm & mesoderm- ecto-skin, endo-digestive track& meso-muscles and other organs betw. skin& digestive track 2 germ layers= diploblastic animals 3 germ layers= triploblastic animals c. Body Cavity Organs formed inside the coelom can freely move, grow, and develop independently of the body wall while fluid cushions and protects them from shocks. Coelomate, Pseudocoelomate, Acoelomate d. Cleavage Protostome & Deuterostome  Chapter 33 1. What makes sponges different than other animals? No tissues 2. What separates Cnidarians (e.g., polyp & medusa) from all other animals? Sponges and cnidarians develop two germ layers during embryonic development: endoderm and ectoderm. No bilateral symmetry. 3. Some flat worms such as tapeworms do not have a mouth and digestive system. How do they feed themselves? They absorb nutrition through their body surface. 4. Rotifers are pseudocoelomates. What is that mean? They have mesoderm but their body cavity is not completely lined by mesoderm. It is between endoderm and mesoderm. 5. The phyla Mollusca and Annelida belong to a clade called Lophotrochozoa. What do separate them? Mollusks- shell, annelids-segmented body. 6. The two ecdysozoan phyla, the nematodes and arthropods are among the most diverse groups. What are the differences and similarities in their body plan? External coat made of cuticle, molting (ecdysis) 7. What are some of the adaptations that enabled insects to thrive on land? Exoskeleton, wings and small size 8. What are the major arthropod groups? Major mollusk groups?  Chapter 34 Mammalian Diversity & Phylogenetic Relationship will not be included in the exam (pp. 742-752). 1. Why is it that echinoderms are the sister groups to all chordates? See the figure below for the answer. 2. All vertebrates are chordates, but not all chordates are vertebrates. Explain. 3. What characteristics define chordates? 4. Jawless vertebrates have been far outnumbered by the jawed vertebrates, gnathostomes. Explain the evolutionary significance of havening a jaw. It allowed fish to transition from passive filter feeding to active predation, wider food choice, more efficient digestion. 5. What did the gnathostome jaw evolved from? See the figure below for the answer. 6. What is the importance of lob finned fish structure in vertebrate evolution? Lob fins allow fish to carry their body weight outside water.  7. What is the importance of lung fish in vertebrate evolution? Breathing free oxygen in the air, an adaptation for living away from water. 8. What is wrong with the following sentence? The fossil Tiktaalik exhibits both fish and vertebrate characters". It shows the transition from fish to a tetrapod reptile. 9. What are the key amniote adaptations for life on land? 10. What are the major derived characters of mammals? Mammary glands, hair, kidney, larger brain size, the jaws bear a variety of teeth, modified jaw bones that transmit sound in the ear. 11. Contrast monotremes, marsupials, and eutherians in terms of how they bear their young. Chapter 40 & 48 Concepts only 40.1, 40.2, 48.1, 48.2, 48.3 will be included in the exam. 1. How are body forms and shapes correlated with function? 2. What are the four major tissues in mammals? 3. Explain what "homeostasis" is? 4. What is action potential? 5. What happens when a resting neuron's membrane depolarizes? 6. Acetylcholine is a neurotransmitter. Where is it found in a nerve cell? What is the function of it? Ch 37 WILL NOT BE INCLUDED IN THE EXAM