Cocklebur Will Not Flower If Exposed to 8 Hours of Dark

question 37

Multiple Choice

Cocklebur will not flower if exposed to 8 hours of dark and 16 hours of light.It will flower if exposed to 16 hours of dark and 8 hours of light.However,if the 16 hours of dark is interrupted with a brief period of light the cocklebur will not flower.What triggers cocklebur to flower?

• A) short dark periods
• B) short light periods
• C) long light periods
• D) long dark periods
• E) No answer is correct.