Section: Coach Light — Living with Light
This section covers Chapter 2, Lessons 2.1 through 2.4.
Part A — Vocabulary (20 points, 2 points each)
Select the best answer for each question.
1. Phase advance refers to:
A) A photography term B) A shift of the circadian rhythm earlier C) Increased sleep duration D) The same as phase delay
2. Phase delay refers to:
A) Slow shutter speed B) A shift of the circadian rhythm later C) Going to bed later than usual one night D) The same as phase advance
3. The Phase Response Curve (PRC) is:
A) A graph showing how light at different times of day affects the circadian rhythm B) A measurement of melatonin levels C) A type of sleep tracker D) A medical device
4. Morning light window refers to:
A) The shape of a bedroom window B) The period roughly within 1-2 hours after waking, with strongest phase-advancing effect C) A time of day to avoid screens D) Sunrise time only
5. Pre-sleep window refers to:
A) Time before bed for screens B) The 2-3 hours before normal sleep onset, when light has the strongest effect on sleep C) Time after waking D) Midnight onward
6. UVB radiation drives:
A) Skin aging only B) Vitamin D production and is also responsible for sunburn C) Indoor lighting effects D) Pupil constriction
7. UVA radiation compared to UVB:
A) Is shorter wavelength B) Has longer wavelength, penetrates more deeply, and is associated with skin aging and some cancers C) Produces vitamin D D) Is filtered by ordinary glass
8. Seasonal Affective Disorder (SAD) is:
A) A separate condition unrelated to depression B) A specifier of depression with a seasonal pattern; most common in winter C) A type of allergy D) A purely physical condition
9. Functional brightness refers to:
A) Brightness of a lamp's bulb B) The amount of light actually reaching the eye in a given situation C) Total light output of a fixture D) A photography term
10. Light hygiene describes:
A) Cleaning light fixtures B) Practices around when and how to be exposed to light, paralleling sleep hygiene C) Avoiding all artificial light D) A medical protocol
Part B — Concept Comprehension (20 points, 2 points each)
Select the best answer for each question.
11. Morning light has its strongest biological effect on the circadian clock because:
A) Eyes are more sensitive in the morning B) The phase response curve shows light at this time produces phase advances C) Cortisol is highest in the morning D) Melatonin is highest in the morning
12. Direct sun-staring is dangerous because:
A) It causes eyelid sunburn B) It can cause solar retinopathy and permanent retinal damage in seconds C) It releases too much vitamin D D) It harms the SCN directly
13. Vitamin D is produced in the skin when which type of light interacts with a cholesterol-derived compound?
A) UVA B) UVB C) Visible blue light D) Infrared
14. Nitric oxide release from the skin during sun exposure is associated with:
A) Skin cancer B) Vitamin D depletion C) Modest reductions in blood pressure D) Higher resting heart rate
15. Sunburn is best described as:
A) A sign of healthy sun exposure B) Visible tissue damage from UVB C) A precursor to vitamin D D) A normal tanning stage
16. Light wavelengths around 460-480 nm (blue-cyan):
A) Are invisible to humans B) Most strongly activate ipRGCs and suppress melatonin C) Cause sunburn D) Have no effect on the body
17. Research on adolescent screen use before sleep has consistently observed:
A) No measurable effects B) Improved sleep C) Later bedtimes, longer sleep onset latency, and shorter total sleep duration D) Earlier melatonin onset
18. Seasonal affective disorder is classified as:
A) A separate disorder B) A specifier of depression with a seasonal pattern C) A form of anxiety D) A purely physical condition
19. Bright light therapy for SAD is described as:
A) Something to start independently after reading online B) A medical intervention requiring healthcare provider guidance C) Identical to ordinary morning light D) Not supported by research
20. Reflected light refers to:
A) Light that bounces back into a mirror only B) Light that reaches the eye after bouncing off the surrounding environment C) Light blocked by clothing D) The same as direct sunlight
Part C — Application (30 points, 6 points each)
Write 2-4 complete sentences for each question. Show your reasoning.
21. Describe the phase response curve in your own words. What does it suggest about light at different times of day, and what is one practical implication for an adolescent?
22. Explain how UVB light contributes to vitamin D production and identify several body functions vitamin D supports.
23. Walk through the case for "thoughtful sun exposure." Why is the Rooster's frame not simply "more sun" or "less sun"?
24. Why is the pre-sleep window (last 2-3 hours before sleep) the most important time for evening light hygiene? Reference specific structures and pigments.
25. The chapter describes adolescent biology as naturally shifted later and modern school schedules as starting early. What is the resulting structural conflict, and what can students do about it?
Continue to the next section.