Photoperiodism in Plants

Photoperiodism is the ability of plants to respond to light and darkness cycles. It regulates flowering, growth, and leaf loss in plants. Plants are classified as long-day, short-day, or day-neutral based on their response to light. Long-day plants need more than 12 hours of light to bloom, while short-day plants require less than 12 hours. Day-neutral plants flower regardless of light duration. Examples include Irises and lettuce for long-day, Chrysanthemums for short-day, and tomatoes for day-neutral.

What is photoperiodism primarily responsible for in plants?

• Photosynthesis

• Regulating flowering and growth

• Seed germination

• Water absorption

How are flowering plants classified based on their response to light and darkness?

• Deciduous, evergreen, coniferous

• Tropical, temperate, arctic

• Long-day, short-day, day-neutral

• Annual, biennial, perennial

Which of the following is a characteristic of long-day plants?

• They bloom only in winter

• They bloom with less than 12 hours of light

• They require more than 12 hours of light to flower

• They are unaffected by light duration

Which of these plants is an example of a short-day plant?

• Lettuce

• Tomato

• Chrysanthemum

• Rice

What is unique about day-neutral plants?

• They require a specific light duration to flower

• They flower regardless of light and darkness periods

• They only bloom in summer

• They are sensitive to temperature changes