pho·to·pe·ri·od·ism 
(fō′tō-pîrē-ə-dĭz′əm)
(fō′tō-pîrē-ə-dĭz′əm)n.
An organism's response or ability to respond to changes in photoperiod.
- bestowable
- bestowal
- bestowment
- bestrew
- bestride
- bestseller
- best seller
- bestsellerdom
- best-selling
- be stuck on
- bet
- beta
- beta-adrenergic
- beta-adrenergic antagonist
- beta-adrenergic blocker
- beta-adrenergic receptor
- beta-agonist
- beta-amyloid
- beta-blocker
- beta carotene
- beta-carotene
- beta cell
- beta decay
- beta-endorphin
- beta error