Photoperiodism

Q. Assertion: Shoot apices tend to modify themselves into flowering apices before flowering. Reason: Shoot apices can’t perceive photoperiods.

1. Both assertion and reason are correct and the reason is the correct explanation to the assertion
2. Both assertion and reason are correct but the reason is an incorrect explanation to the assertion
3. Only assertion is correct
4. Both are incorrect statements

Q. _________are the site of perception for photoperiodic stimulation

1. Roots
2. Stem
3. Shoot apices
4. Leaves

Q. Why is vivipary an undesirable character for annual crop plants?

1. It reduces the vigour of the plant.
2. It adversely affects the fertility of the plant.
3. The seeds exhibit long dormancy.
4. The seeds cannot be stored under normal conditions for the next season.

Q. Among bitter gourd, mustard, brinjal, pumpkin, china rose, lupin, cucumber, sunnhemp, gram, guava, bean, chilli, plum, petunia, tomato, rose Withania, potato, onion, aloe and tulip how many plants have hypogynous flower?

1. Ten
2. Fifteen
3. Eighteen
4. Six

Q. What happens during vegetative growth in plants?

1. They develop leaves
2. They produce pollen grains
3. They produce ovules
4. They develop flowers

Q. Circadian rhythms are

1. daily (24 Hr) rhythms
2. monthly rhythms
3. annual rhythms
4. seasonal rhythms

Q.

Would a defoliated plant respond to photoperiodic cycle? Why?

Q.

Phototropic curvature is the result of uneven distribution of:

1. Phytochrome

2. Gibberellin

3. Auxin

4. Cytokinins

Q. Photoperiodism was first characterized in

1. Tobacco
2. Potato
3. Tomato
4. Cotton

Q. Assertion: Chrysanthemum is flashed with 660 nm of light, the flower does not bloom even if the light period is well below the critical photoperiod. Reason: Chrysanthemum is a long-day flowering plant.

1. Both assertion and reason are correct statements and reason is the correct explanation to the assertion
2. Both assertion and reason are correct statements and reason is an incorrect explanation to the assertion
3. Only assertion is correct
4. Both assertion and reason are incorrect

Q. Fruit drop is caused by

1. more auxin in fruit than in stem
2. less auxin in fruit than in stem
3. equal distribution of auxin in stem and fruit
4. absense of auxin in stem and fruit

Q.

What is a plant pigment responsible for photoperiodism?

Q. _________are the site of perception for photoperiodic stimulation

1. Roots
2. Stem
3. Shoot apices
4. Leaves

Q.

The growth of the pollen tube towards the ovule is an example of

1. Phototropism

2. Hydrotropism

3. Thigmotropism

4. Chemotropism

Q. Curling of tendrils is due to a growth movement called

1. thigmotropism
2. phototropism
3. chemotropism
4. nyctinasty

Q.

What is phototropism? Name any plant hormone that controls phototropism.

Q.

Which hormone is responsible for photoperiodism?

Q.

Guard cells _______ during the day and ______ at night.

Q.

Photoperiod affect the ________.

Q. Assertion: A defoliated plant can respond to photoperiodic stimulation.

Reason: It is the shoot apices that perceive light to induce flowering.

Select the appropriate option:

1. Both assertion and reason are correct statements and the reason is the correct explanation of the assertion
2. Both assertion and reason are correct statements but the reason is an incorrect explanation of the assertion
3. Only assertion is correct
4. Both assertion and reason are incorrect

Q.

What do you mean by phytochrome?

Q. Assertion: A defoliated plant can respond to photoperiodic stimulation.

Reason: It is the shoot apices that perceive light to induce flowering.

Select the appropriate option:

1. Both assertion and reason are incorrect
2. Both assertion and reason are correct statements and the reason is the correct explanation of the assertion
3. Both assertion and reason are correct statements but the reason is an incorrect explanation of the assertion
4. Only assertion is correct

Q. In decapitated plants, axillary buds are activated because

1. auxin is made available to them
2. more food material is available to them
3. amount of cytokinin increase in them
4. they get more light

Q.

Phytochrome is found in

1. Algae

2. Fungi

3. Vascular cryptogams

4. Flowering plants

Q. Assertion : Dark period is equally important for flowering like the light period
Reason : Flowering occurs in short day plants if the dark period is interrupted by light period

1. Both assertion and reason are false
2. Both assertion and reason are true and the reason is the correct explanation of assertion
3. Both assertion and reason are true but the reason is not the correct explanation of assertion
4. Assertion is true but reason is false

Q. The minimum length of the day or photoperiod required to induce flowering in a plant is called its .

1. photoperiodism
2. critical day length
3. vernalisation
4. critical dark length

Q.

Mention the unit flowering phenomenon exhibited by strobilanthus?

Q.

What Hormone Controls Phototropism?

Q. Certain pigments regulate the process of photoperiodism. The pigments exist in two photochemically inter-convertible forms, operating at two different wavelength of light.
The pigments in question are the:

1. Carotenoids
2. Xanthophylls
3. Chlorophylls
4. Phytochromes

Q. Stomatal opening is affected by

1. Nitrogen concentration, carbon dioxide concentration and light
2. Carbon dioxide concentration, temperature and light
3. Nitrogen concentration, light and temperature
4. Carbon dioxide concentration, nitrogen concentration and temperature