BIO 100 EXAM 3 QUESTIONS AND ANSWERS ALREADY PASSED

BIO 100 EXAM 3 QUESTIONS AND ANSWERS ALREADY PASSED **Explain the roles of different body systems: digestive, cardiovascular (respiratory and circulatory), immune, skeletal/muscular, endocrine, reproductive, and nervous.** - **Digestive System**: Breaks down food and absorbs nutrients for energy. - **Cardiovascular System**: - **Respiratory**: Facilitates oxygen intake and carbon dioxide expulsion. - **Circulatory**: Transports nutrients, metabolic wastes, water, salts, and immune cells throughout the body. - **Immune System**: Defends against diseases and harmful substances. - **Skeletal/Muscular System**: Provides structure, protection, and facilitates movement. - **Endocrine System**: Produces hormones that regulate bodily functions. - **Reproductive System**: Produces and transports egg and sperm cells, supports fetal development, and produces reproductive hormones. - **Nervous System**: Controls body activities and responds to stimuli. **What does it mean for an organism to be an ectotherm or an endotherm? Give examples.** - **Ectotherm (cold-blooded)**: Animals whose body temperature is regulated by external environmental conditions, such as sunlight. Example: Lizards, frogs, turtles, and most fish. - **Endotherm (warm-blooded)**: Animals that can generate and maintain their body heat internally. Example: Mammals and birds. **Why do herbivorous mammals have long digestive systems, omnivores have intermediate lengths, and carnivores have short intestines?** Herbivores need long digestive tracts to efficiently break down and absorb nutrients from fibrous plant material. Omnivores have intermediate length intestines to process both plant and animal matter. Carnivores have short digestive tracts as they quickly obtain nutrients from animal proteins and fats. **Why do strict vegetarians (vegans) need to be more careful with their food choices compared to vegetarians who consume cheese, eggs, and dairy products?** Vegans avoid all animal products and primarily consume "incomplete proteins" lacking some essential amino acids. Vegetarians who consume dairy and eggs can obtain "complete proteins," which contain all necessary amino acids. **Describe the breathing process, including the actions of the diaphragm and the concepts of positive and negative pressure.** - **Inhalation**: The diaphragm contracts and moves downward, increasing chest cavity space and lowering internal pressure, causing air to flow into the lungs as they expand. Intercostal muscles also lift the rib cage upward and outward. - **Exhalation**: The diaphragm relaxes and moves upward, decreasing chest cavity space and increasing internal pressure, pushing air out of the lungs. **How do vaccines function?** Vaccines target viruses and initiate a preemptive immune response. They typically contain weakened or inactive parts of a virus, prompting the immune system to produce antibodies without causing the disease, preparing the body to recognize and fight the virus in future exposures. **What effect does the disintegrin protein in Southern Copperhead snake venom have on its prey?** Disintegrin interferes with blood clot formation by preventing platelets from aggregating at the injury site, allowing the venom to spread more easily throughout the prey's body. **Give examples of how surface area is maximized in the human digestive, respiratory, and nervous systems.** - **Digestive System**: The intestines have folds, microvilli, and villi that significantly increase the surface area for nutrient absorption. - **Respiratory System**: The alveoli in the lungs provide a large surface area for gas exchange. - **Nervous System**: The extensive branching of neurons and the presence of dendrites increase the surface area for synaptic connections and neural communication.. Respiratory System- In the lungs there are small sacs called alveoli. These contain the respiratory surfaces we need to breathe. These greatly increase the surface