[Campbell Biology P.932] Based on Figure 40.9a, which of the following statements accurately... | Practice Question

Based on Figure 40.9a, which of the following statements accurately describes the relationship between melatonin concentration and core body temperature during a 24-hour cycle?

  • A: Melatonin concentration and core body temperature both peak around 6 AM.
  • B: Melatonin concentration is highest when core body temperature is at its lowest.
  • C: Both melatonin concentration and core body temperature decrease significantly during the daytime.
  • D: Melatonin concentration starts to rise as core body temperature begins to increase.

Explanation

Figure 40.9a shows that melatonin concentration peaks around 2 AM to 4 AM, which is precisely when the core body temperature reaches its lowest point around 4 AM to 6 AM .