Bio 132 Exam 3 Questions and Answers|2025 Update

Bio 132 Exam 3 Questions and Answers|2025 Update Protostome - Answer- Animal in which the blastopore develops into the mouth during early development Deuterostome - Answer- Animal in which the blastopore develops into the anus Lophotrochozoans - Answer- Protostomes that grow continuously and may have a lophophore or trochophore larva Ecdysozoans - Answer- Protostomes that grow by molting (ecdysis) their exoskeleton Ecdysis - Answer- Process of shedding outer covering to grow Lophophore - Answer- Feeding structure with tentacles used for filter feeding Trochophore - Answer- Free-swimming larval stage with cilia Flatworms (Platyhelminthes) - Answer- Soft-bodied, flat animals with no body cavity and simple organ systems Flatworm Adaptations - Answer- Flat shape allows gas exchange by diffusion; simple nervous system; many are parasitic Nematodes - Answer- Roundworms with cuticle that molt; complete digestive system Annelids - Answer- Segmented worms with true coelom and advanced organ systems Segmentation - Answer- Body divided into repeating units, improves movement and specialization Mollusk Body Plan - Answer- Foot (movement), visceral mass (organs), mantle (may secrete shell) Arthropods - Answer- Animals with exoskeleton, jointed appendages, and segmented bodies Exoskeleton - Answer- Hard outer covering made of chitin Complete Metamorphosis - Answer- Development with larva and pupal stages (egg → larva → pupa → adult) Incomplete Metamorphosis - Answer- Development without pupal stage (egg → nymph → adult) Echinoderms - Answer- Marine animals with radial symmetry, calcium carbonate skeleton, and tube feet Water Vascular System - Answer- Hydraulic system used for movement and feeding in echinoderms Keystone Species - Answer- Species with a disproportionately large effect on ecosystem stability Chordates - Answer- Animals with notochord, dorsal nerve cord, pharyngeal slits, and post-anal tail Notochord - Answer- Flexible rod that provides support Dorsal Hollow Nerve Cord - Answer- Develops into brain and spinal cord Pharyngeal Slits - Answer- Openings used in feeding or respiration Post-Anal Tail - Answer- Tail extending beyond the anus Vertebrates - Answer- Chordates with backbone and skull Cranium - Answer- Skull that protects brain Vertebrae - Answer- Bones protecting spinal cord Gnathostomes - Answer- Jawed vertebrates Evolution of Jaws - Answer- Allowed organisms to capture and process food more effectively Chondrichthyes - Answer- Cartilaginous fish like sharks and rays Ray-Finned Fish - Answer- Bony fish with fin rays and swim bladder Swim Bladder - Answer- Organ that controls buoyancy Tetrapods - Answer- Vertebrates with four limbs Amphibians - Answer- First tetrapods; require water for reproduction Amniotic Egg - Answer- Egg with membranes that allow reproduction on land Reptiles - Answer- Amniotes with keratin scales and eggs Mammals - Answer- Animals with hair, milk production, and endothermy Endothermy - Answer- Ability to regulate body temperature internally Placenta - Answer- Organ that provides nutrients and oxygen to developing embryo Viviparous - Answer- Give birth to live young Oviparous - Answer- Lay eggs Parental Care - Answer- Investment in offspring to increase survival, but requires energy Neuron - Answer- Specialized cell that transmits electrical signals Dendrites - Answer- Receive incoming signals Axon - Answer- Transmits signal away from neuron Membrane Potential - Answer- Voltage difference across membrane due to ion distribution Resting Potential - Answer- Stable negative charge inside neuron (~ -70 mV) Sodium-Potassium Pump - Answer- Actively transports 3 Na⁺ out and 2 K⁺ in Electrochemical Gradient - Answer- Combined force of concentration and electrical gradients