Section C — Coach Sleep — Sleep and Your Phone
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. A circadian rhythm is:
A) A weekly schedule B) A roughly 24-hour internal biological clock — controls when you feel alert, sleepy, hungry, and many other daily cycles C) Only present in adults D) A type of dream
2. The SCN (suprachiasmatic nucleus) is:
A) The brain's master clock — about 20,000 neurons in the hypothalamus, just above where the optic nerves cross B) A type of muscle C) A bone in the skull D) Always silent
3. Melatonin is:
A) A vitamin B) A hormone released by the pineal gland in the evening that signals "it's dark, time to wind down for sleep" C) A neurotransmitter for attention D) Always present in equal amounts day and night
4. The pineal gland is:
A) A type of muscle B) A small gland deep in the brain that makes and releases melatonin C) A part of the lung D) The same as the SCN
5. Entrainment is:
A) Going on a vacation B) The process of your body clock being synchronized to outside signals — mostly light C) Sleeping less than usual D) A train ride
6. Blue-wavelength light is:
A) Only found in oceans B) Short-wavelength visible light (about 460-480 nm) — the band that most strongly affects ipRGCs and melatonin C) Light that cannot be seen D) Only present at night
7. Phase delay is:
A) Sleep happening earlier than expected B) A shift of the body clock to a later time — caused by light in the late afternoon and evening C) The same as deep sleep D) Only seen in adults
8. Sleep onset latency is:
A) The age you started sleeping B) The time between trying to fall asleep and actually falling asleep C) The number of hours you sleep D) The same as REM sleep
9. Adolescent sleep phase delay describes:
A) Teenagers being lazy on purpose B) The well-documented biological tendency for adolescents to have circadian rhythms shifted approximately 1-2 hours later than children or older adults C) Sleep stopping during puberty D) Sleep only at lunch
10. Social jet lag is:
A) Travel-related fatigue B) The pattern of different sleep schedules on school days versus weekends — produces effects similar to mild jet lag C) A clinical disease D) A type of dream
Part B — Concept Comprehension (20 points, 2 points each)
Select the best answer for each question.
11. The natural cycle length of the human circadian rhythm without outside cues is approximately:
A) Exactly 12 hours B) Slightly less than 24 hours C) Slightly longer than 24 hours (about 24.2 hours) D) 48 hours
12. The strongest zeitgeber (time-giver) in humans is:
A) Food B) Light C) Exercise D) Social schedule
13. Melatonin in a healthy schedule begins to rise approximately when?
A) About 2 hours before normal sleep onset (the "dim light melatonin onset" or DLMO) B) Only after you are asleep C) At noon D) Only on weekends
14. A bright phone screen at 11 p.m. tends to:
A) Have no effect on sleep B) Suppress melatonin release by activating ipRGCs in the retina with blue-cyan wavelengths C) Increase melatonin release D) Replace the need for sleep
15. Research has consistently observed that heavy evening screen use is associated with:
A) Earlier sleep onset and better sleep quality B) Later bedtimes, longer sleep onset latency, shorter sleep, lower sleep quality, and more daytime fatigue C) Only better mood D) No measurable effect
16. The teen circadian rhythm naturally shifts:
A) Earlier B) Later by about 1-2 hours compared to younger children — biology, not laziness C) The same as a 6-year-old D) Backwards in time
17. Teen sleep need is approximately:
A) About 4-6 hours B) About 8-10 hours, with most middle schoolers needing closer to 9-10 C) About 12 hours every night D) Zero
18. Useful evening light practices include:
A) Maximum overhead light brightness right up to bedtime B) Dimming the room, lowering screen brightness, using night mode, increasing distance from screens, and protecting a dark sleep environment C) Staring into bright lights for the last hour D) Only sleeping with the TV on
19. When school start times are very early and teen biology is shifted later, the result is:
A) Improved test performance B) Chronic sleep loss that the individual student cannot fully fix on their own — structural mismatch between biology and schedule C) No effect on adolescents D) Better mood overall
20. Coach Sleep at Grade 7's main message is:
A) Phones are evil B) Light and behavior interact with circadian biology in measurable ways; understanding the system gives you small reliable levers to support sleep even when the schedule is hard C) You should sleep all day D) Adolescents need less sleep than children
Part C — Application (30 points, 6 points each)
Write 2-4 complete sentences for each question.
21. Trace the path of a morning light signal from the eye to the rest of the body. Use the terms ipRGCs, retinohypothalamic tract, SCN, and pineal gland.
22. Why does a bright phone screen at 11 p.m. cause sleep problems but not at 1 p.m.? Explain in terms of when melatonin is supposed to be rising.
23. Describe adolescent sleep phase delay. Why is it biology, not "laziness"? Why does this cause a structural mismatch with most school start times?
24. Two students sleep the same total hours, but Student A goes to bed at 9 p.m. and wakes at 6 a.m.; Student B goes to bed at 11 p.m. on school nights and 2 a.m. on weekends, then sleeps until 11 a.m. Which student probably has worse circadian alignment, and why?
25. Suggest three practical evening adjustments a middle schooler can make to protect sleep without giving up screens entirely. For each, explain briefly how it affects melatonin or the SCN.
Continue to Section D — Coach Move.