#photoperiodism MCQ

PSS-Sec-E-Sensory biology

Long-day plants flower when:

Night length < critical (B) is correct here. This is core PSS-Sec-E-Sensory biology: once you know the definition or pathway step, Night length < critical is the clear fit. The wrong ones are A) Day length < critical; C) Night length > critical; D) Under darkness. If the topic is about gradients or potentials, water/solutes move from higher to lower of the relevant quantity.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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PSS-Sec-E-Sensory biology

Which photoreceptor perceives day length and circadian rhythms?

Correct option is C, Zeitlupe. In PSS-Sec-E-Sensory biology problems like this, the accurate statement is Zeitlupe; the others are common mix-ups. Not these: A) Cryptochrome; B) Phototropin; D) UVR8. Tissue transport questions usually turn on xylem vs phloem, living vs dead cells, or source vs sink.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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PHOTOPERIODISM+PYQS

Which of the following is a long-short day plant?

The right choice is B: Bryophyllum. In PHOTOPERIODISM, that matches how the process or concept actually works — the other choices mix up related ideas or use the wrong mechanism. Skip these: A) Trifolium; C) Rice; D) Wheat. A quick check: if an option needs energy, pumps, or the opposite direction of movement, ask whether that really applies.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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PHOTOPERIODISM+PYQS

Short-long day plants flower after:

Correct option is B, Short days followed by long days. In PHOTOPERIODISM problems like this, the accurate statement is Short days followed by long days; the others are common mix-ups. Not these: A) Long days followed by short days; C) Only short days; D) Only long days. Tissue transport questions usually turn on xylem vs phloem, living vs dead cells, or source vs sink.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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PHOTOPERIODISM+PYQS

Long-short day plants flower after:

That points to C: Sequence of long days followed by short days. Compared with the other options, Sequence of long days followed by short days is the one that correctly describes the PHOTOPERIODISM concept. The wrong ones are A) Only long days; B) Only short days; D) Random photoperiod. If you’re stuck, eliminate anything that contradicts a basic fact you already know for this topic.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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PHOTOPERIODISM+PYQS

Exposure to far-red light reverses the effect of:

B fits best: Red light. Keep the PHOTOPERIODISM basics straight and Red light stands out as the precise answer. Avoid: A) Blue light; C) UV light; D) Green light. Light and flowering items often hinge on which photoreceptor or day-length rule is in play.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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PHOTOPERIODISM+PYQS

Night break treatment is most effective when given:

Answer: C) In middle of dark period. For PHOTOPERIODISM, remember the key idea and you’ll land on this option; the distractors usually swap cause and effect or confuse similar terms. Avoid: A) At beginning of night; B) At end of night; D) During day. Name the process first, then pick the option that describes it — don’t reverse cause and effect.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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PHOTOPERIODISM+PYQS

Interruption of dark period by red light in short day plants results in:

Go with C — Inhibition of flowering. Under PHOTOPERIODISM, this is the standard explanation you’d use in class: it names the real driver or definition, while the rest are nearby but wrong. Not these: A) Flowering; B) No effect; D) Early flowering. When two options sound similar, choose the one that matches the textbook definition most tightly.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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PHOTOPERIODISM+PYQS

In short day plants, flowering occurs when there is:

The right choice is B: Low or absence of Pfr. In PHOTOPERIODISM, that matches how the process or concept actually works — the other choices mix up related ideas or use the wrong mechanism. Skip these: A) High Pfr; C) Continuous red light; D) High Pr accumulation. A quick check: if an option needs energy, pumps, or the opposite direction of movement, ask whether that really applies.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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PHOTOPERIODISM+PYQS

In long day plants, flowering is promoted by:

Correct option is B, Presence of Pfr. In PHOTOPERIODISM problems like this, the accurate statement is Presence of Pfr; the others are common mix-ups. Not these: A) Absence of Pfr; C) Low phytochrome; D) High Pr. Tissue transport questions usually turn on xylem vs phloem, living vs dead cells, or source vs sink.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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PHOTOPERIODISM+PYQS

Which of the following is a short day plant?

Go with C — Rice. Under PHOTOPERIODISM, this is the standard explanation you’d use in class: it names the real driver or definition, while the rest are nearby but wrong. Not these: A) Wheat; B) Barley; D) Pea. When two options sound similar, choose the one that matches the textbook definition most tightly.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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PHOTOPERIODISM+PYQS

Which of the following is a long day plant?

Go with C — Wheat. Under PHOTOPERIODISM, this is the standard explanation you’d use in class: it names the real driver or definition, while the rest are nearby but wrong. Not these: A) Rice; B) Maize; D) Potato. When two options sound similar, choose the one that matches the textbook definition most tightly.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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