1. Graphing Activity & 4 Questions
AP Bio 2017

2. A good title? Heating Curve of Water Over Time
Specific Heat of Water over Time

3. Dependent variable
Temperature in oC

4. Independent variable
Time in minutes

5. Sample Graph Note the temp labels, as per your instructions:
Ice- below 0 oC
Water- 0 to 100 oC
Steam- above 100 oC
Melting- at 0 oC
Evaporating- at 100 oC

6. Ice melts at 0 oC, water boils at 100 oC Rationale for each?
Question 1: At what temperature(s) does ice begin to melt and water begin to boil? How do you know? Answer with scientific rationale.
Ice melts at 0 oC, water boils at 100 oC
Rationale for each?
At these temperatures, with no addition/removal of heat energy, the state (solid or liquid) won’t change- stays at 0oC / 100 oC until all converted liquid or vapor (steam)

8. Question 2: Which water transformation best lends itself to ensuring that organisms do not overheat? Explain.
Vaporization/Evaporation/Heat of vaporization/Evaporative cooling- “dissipates body heat” as the “hottest molecules- those with the greatest kinetic energy- leave the body as a gas” (Reece et al, 2011)

9. Question 3: Which water transformation best lends itself as a barrier, ensuring that aquatic organisms are protected against cold air?
Water to solid ice formation- ice barriers act as insulators and prevent cold air from reaching organisms.

10. Question 4 Which water property best lends itself to ensure that aquatic organisms are able to maintain homeostasis relative to their own temperature fluctuations?
Water’s high specific heat: “because organisms are made primarily of water, they are better able to resist changes in their own temperature than if they were made of a liquid with a lower specific heat” (Reece, et al. 2011)

11. Make sense now?