use photoperiod in a sentence.
Taken together, our findings suggest that optimization of experimental conditions such as photoperiod may be necessary to visualize FAA in genetically modified mice.
The changing of day length in spring and fall triggers bird migration because "photoperiod" is the only absolutely reliable environmental cue that signals birds that it's
I know rut is driving by photoperiod, but what about the effect of a really warm snap?
Reindeer, like several other species of deer, show a pronounced seasonal cycle in appetite and growth which appears to follow an intrinsic rhythm entrained by photoperiod and associated with changes in levels of circulating hormones.
"The photoperiod transducer melatonin and the immune-hematopoietic system".