Question

Which of the following statements is/are correct?

i. At a given place, both long day and short-day plants can flower simultaneously.

ii. Life span of a cabbage plant is nearly two years.

iii. Carrots are polycarpic plants.

• A. Both i and ii
• B. Both i and iii
• C. Only iii
• D. Only i

Answer 1

The correct option is A Both i and ii

Photoperiodic stimulation or photoperiodism is defined as the response by an organism to the lengths of day and night. This duration of day and night is also termed as photoperiod. Certain plants require a definite photoperiod to induce flowering called critical photoperiod. Based on this plants are divided into:

i. Long-day plants: These are those plants that require a longer period of light than a critical photoperiod.

ii. Short-day plants: These are those plants that require a shorter period of light than a critical photoperiod.

iii. Day-neutral plants: The flowering in these plants is not affected by the exposure to light duration.

It is possible that at a given place, both long day and short-day plants can flower simultaneously. For example, if a short day plant requires light for less than 12 hours and a long day plant requires light for more than 10 hours then both plants will flower simultaneously in a light period between 10 to 12 hours.

Cabbages are biennial plants that have a lifespan of 2 years. Other examples include sugarbeet and carrots.

Polycarpic plants produce flowers and seeds multiple times in their lifetime, e.g., Mangifera indica, Citrus reticulata, etc.

Carrots are monocarpic plants that produce flowers and seeds only once in their lifespan. Biennial plants are monocarpic.