Question
Biology Question on plant growth and development
Which of the following plants requires light exposure less than the critical period to initiate flowering?
A
Tobacco
B
Wheat
C
Spinach
D
Oat
Answer
Tobacco
Explanation
Solution
Critical photoperiod is that continuous duration of light which must not be exceeded in short day plants and should always be exceeded in long day plants in order to bring them to flower. Tobacco is a short day plant (SDP), which flowers when the photoperiod is less than the critical period. Wheat, spinach and oat are all long day plants (LDP), which flower when they receive photo period or light hours above the critical photoperiod.