Prepare for NEET Biology Plant Growth and Development (Photoperiodism) with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert insights into effects of day length on flowering and seasonal growth.
NEET Questions / Botany / Plant Growth and Development / Photoperiodism
A short-day plant is exposed to a flash of red light during the critical dark period. This is immediately followed by a flash of far-red light. What is the most likely outcome?
Flowering will be inhibited.
Flowering will be promoted.
The plant will become a long-day plant.
The far-red light will have no effect.
A plant species exhibits a critical dark period of 14 hours. Which of the following light/dark regimes would MOST LIKELY prevent flowering?
10 hours light / 10 hours dark
14 hours light / 10 hours dark
10 hours light / 14 hours dark
15 hours light / 9 hours dark
A long-day plant with a critical dark period of 9 hours is grown under short-day conditions. Which treatment is MOST LIKELY to induce flowering?
Increasing the ambient temperature during the dark period.
Spraying the plant with gibberellins during the light period.
Interrupting the dark period with a brief exposure to red light.
Exposing the plant to far-red light at the end of the dark period.
Phytochrome is involved in many plant responses besides flowering. Which of the following is NOT a known role of phytochrome?
Seed germination
Shade avoidance response
Regulation of stomatal closure
Photomorphogenesis
Researchers discover a new plant pigment, 'florigen X,' that they hypothesize is the elusive 'flowering hormone.' Which experiment would provide the STRONGEST evidence for this hypothesis?
Measuring florigen X levels in leaves of plants grown under different light regimes.
Applying purified florigen X to the apical meristem of a non-induced plant and observing flowering.
Demonstrating that florigen X synthesis is regulated by phytochrome.
Grafting a leaf from a photoperiodically induced plant onto a non-induced plant of the same species and observing flowering in the recipient plant.
Which of the following best describes photoperiodism?
The response of plants to the intensity of light.
The response of plants to the quality of light.
The response of plants to gravity.
The response of plants to the length of day and night.
Plants that flower when the light period is shorter than a critical length are called:
Long-day plants
Short-day plants
Day-neutral plants
Intermediate-day plants
Which pigment is responsible for absorbing light in photoperiodism?
Chlorophyll
Carotenoids
Phytochrome
Xanthophyll
Poinsettia is an example of a:
Long-day plant
Short-day plant
Day-neutral plant
Biennial plant
Spinach is an example of a:
Long-day plant
Short-day plant
Day-neutral plant
CAM plant
