1. the first forms of life on earth a. appeared about 10,000 years ago b. could easily maintain a stable internal environment c. were single-celled d. depended on the hypothalamus for thermoregulation. 2. in an embryo, the tissues that receive a nerve produce sprouting factor, which encourages nerves to grow and branch, while the nerve produces anti-sprouting factor, which inhibits nerve growth. this is an example of a. a positive feedback system b. a negative feedback system c. thermoregulation d. homeostasis. 3. intercellular fluids a. tend to remain constant despite changing conditions b. were found by claude bernard to have widely varying ph c. do not play a role in homeostasis d. are contained in the capillaries in vertebrates. 4. you observe that your cat sprawls on the cool tile floor in the kitchen on hot summer days and curls up in front of a heating vent in the winter. this suggests that a. cats have trouble thermoregulating b. something is wrong with the cat’s hypothalamus c. behavior can play a role in homeostasis d. cats know how to find the most comfortable place in a house. 5. which structure detects and to maintain body temperature in humans? a. spine b. hypothalamus c. pituitary gland d. medulla 6. a child having a tantrum in a department store screams louder the more upset his parent gets. this is an example of a. negative feedback b. positive feedback c. survival of the fittest d. dynamic equilibrium. 7. which of the following events occurs first? a. the brain sends a signal to the muscles. b. the blood vessels just under your skin become narrow. c. the hypothalamus detects a drop in body temperature. d. you shiver. 8. a dog pants because a. evaporation causes cooling b. evaporation gets rid of excess water in the body c. it is tired d. panting to raise body temperature. 9. which is necessary for a feedback mechanism? a. control unit b. effector c. sensor d. all of these. 10. in moist soil, terry the ameba absorbs as much water from its surroundings as diffuses out of its cell. this is an example of a. homeostasis b. dynamic equilibrium c. thermoregulation d. feedback. 11. which structure regulates breathing rate in humans? a. diaphragm b. lungs c. hypothalamus d. medulla.