Question

In many plants the change from vegetative to reproductive phase takes place in response to

• A. Mainly the food material available in the soil
• B. The oxygen present in the air
• C. The severity of temperature
• D. The length of the day

Answer 1

Answer: (D)

Plants are classified according to the flower response system as follows-

Short day plants-Plants in response to short days. (Qualitative)

Short day plants(Quantitative)-Plant flowering system being stimulated by short days but not dependent on them for flowering.

Long day plants(Qualitative)-Plant flowers response to long days.

Long day plants(Quantitative)-Plant flowering initiated by long days but not dependent on them for flowering.

Intermediate Plants- Flower in response to a narrow range of photoperiods.

Ambiphotoperiod-Plant flowers in response to long or short days, but not the intermediate periods of the day.

Hence, one of the options among these is the length of the day.

So, the correct option is'length of the day'.