BIO 100 Exam 3 Review Questions – ASU with Complete Solutions

BIO 100 Exam 3 Review Questions – ASU with Complete Solutions **Compare and contrast the roles of positive and negative feedback in maintaining homeostasis. Use these concepts to explain:** a. **Regulating blood glucose levels:** Negative feedback – the pancreas produces insulin to lower high blood sugar levels. b. **Formation of blood clots:** Positive feedback – initial platelets bind to the injury site, attracting more platelets to the area. **What does it mean for an organism to be an ectotherm? Provide an example.** Ectotherms rely on external sources of heat to regulate their body temperature; for example, snakes. **What does it mean for an organism to be an endotherm? Provide an example.** Endotherms generate heat internally to maintain their body temperature; for example, humans. **Why do herbivorous mammals have longer digestive systems compared to omnivores and carnivores?** Plants have tough cell walls that require more time and effort to break down, necessitating a longer digestive tract. **Why must strict vegetarians (vegans) be more cautious with their food choices compared to vegetarians who consume dairy and eggs?** Vegans must ensure they get sufficient vitamins and proteins, which are more readily available in dairy and eggs. **Explain the process of breathing, detailing inhalation and exhalation with reference to positive and negative pressure and diaphragm action.** - **Inhalation:** When inhaling, the diaphragm and intercostal muscles contract, expanding the chest cavity. This expansion lowers the internal pressure below that of the external air, causing air to flow into the lungs. - **Exhalation:** When exhaling, the diaphragm and intercostal muscles relax, reducing the chest cavity's volume. This increases internal pressure above that of the external air, pushing air out of the lungs. **How do vaccines function?** Vaccines stimulate the immune system to produce antibodies, providing immunity against specific diseases. **In Southern Copperhead snake venom, there is a protein called disintegrin that binds to integrin receptors, which platelets use to aggregate at tissue damage sites. What impact does disintegrin likely have on the snake's prey?** Disintegrin disrupts clot formation, allowing the venom to spread more efficiently from the bite site throughout the prey's body. Anatomical designs that increase surface area are common in many body systems. Give examples of how surface area is maximized in the digestive, respiratory, and nervous systems of humans. respiratory: alveoli allow for an increase in surface are, which maximizes gas exchange digestive: it is folded so that the tract can have a lot of meters nervous system: wrinkles in your brain increase surface area What is the role of the lungs with respect to blood circulation and gas exchange? How does this relate to the function of the heart? The alveoli and capillaries both have very thin walls, which allow the oxygen to pass from the alveoli to the blood. The capillaries then connect to larger blood vessels, called veins, which bring the oxygenated blood from the lungs to the heart. Explain the immune's systems different lines of defense 1. First line of defense - mucus and skin 2. Second line of defense - phagocytic cells, inflammation, and fever 3. Specific Resistance (Acquired Immunity) - T-cells and B-cells Why is your immune system usually more effective at fighting off infection the second time you are exposed to a pathogen? Memory B cells Breastfeeding has an additional effect in many women. The hormones important for producing milk and causing milk to be released in reaction