Question

The plants bloom when the light duration is less than 12 hours per day are know as.

• A. Short day plants
• B. Long day plants
• C. Mid day plants
• D. Day neutral plants

Hint:

It's a common misconception that day length is the trigger. The critical factor is actually the length of the uninterrupted dark period. Short-day plants are really long-night plants, and long-day plants are really short-night plants.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Photoperiodism is the response of plants to the relative lengths of light and dark periods. This response, particularly flowering, is crucial for their reproductive success. Plants are categorized based on their photoperiodic requirements for flowering.
Step 2: Detailed Explanation:
Let's define the categories:


Short-day plants (SDPs): These plants flower only when the period of light is shorter than a certain critical length. More accurately, they are "long-night" plants, as they require a continuous period of darkness that is longer than a critical length to induce flowering. Blooming when the light duration is less than 12 hours (implying a night longer than 12 hours) fits this description perfectly. Examples include chrysanthemums, poinsettias, and soybeans.

Long-day plants (LDPs): These plants flower when the light period is longer than a critical length (or the dark period is shorter). Examples include spinach, lettuce, and iris.

Day-neutral plants (DNPs): The flowering in these plants is not dependent on photoperiod but on other factors like age or temperature. Examples include tomatoes, cucumbers, and roses.

Mid-day plants: This is not a standard scientific classification for photoperiodism.

Step 3: Final Answer:
Plants that bloom when the light duration is short (e.g., less than 12 hours) are known as short-day plants.