circadian rhythm
When people work at night, the circadian clock gets knocked off its traditional course, which can have negative biological consequences.
The body's internal circadian clock can be affected by light exposure.
The circadian clock governs everything from flowering to hormone secretion in plants.
SMART Vocabulary: related words and phrases Relating to regular periods of time
afternoons
annual
annum
bi-yearly
biannual
dailiness
daily
daily grind
evenings
fortnightly
hourly
nights
p.c.m.
p.w.
per annum
quadrennial
quadrennially
triennial
triennially
weekly
You can also find related words, phrases, and synonyms in the topics:
Animal & plant biology - general words