Tag: living world of plants - plant physiology

Questions Related to living world of plants - plant physiology

Response of plants due to reversible turgor change in pulvinus as a result of touch is

movement in plants living world of plants - plant physiology biology

  1. Photonasty

  2. Thermonasty

  3. Seismonasty

  4. Chemonasty

Show answer
Correct Option: C
Explanation:

Photonasty is the nastic movement shown by plant part in response to light. Thermonasty is the nastic movement shown by plant part in response to high temperature. Seismonasty is the nastic movement shown by plant part in response to touch. The response of plants due to reversible turgor change in pulvinus as a result of touch is due to seismonasty. Chemonasty is the nastic movement shown by plant part in response to the chemical.

Thus, the correct answer is option C.

Cresco graph was used to.

movement in plants living world of plants - plant physiology biology

  1. Investigate sleep movements of bean leaves

  2. Study the role of phytochrome in seed germination

  3. Record the progress of plant growth

  4. Distinguish between short day plants and long day plants

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Correct Option: A

When touched by an insect, the leaf of Drosera is bent. What is the name of this process?

movement in plants living world of plants - plant physiology biology

  1. Photonasty

  2. Hydronasty

  3. Thigmonasty

  4. Thermonasty

Show answer
Correct Option: C
Explanation:

When the marginal glandular hair of Drosera leaf comes in contact with the insect body, they show thigmonastic (haptonastic) movement. It is the nastic movement (paratonic variation movement) determined by the external stimulus of touch or contact but the direction of movement is prefixed, determined by the structure of the responsive organ. Thus the correct answer is option C.

When mimosa pudica plant is touched or is exposed to a shock or mechanical blow the leaflets close upwards and the lower side of the petiole contracts.

movement in plants living world of plants - plant physiology biology

  1. Epinasty

  2. Nyctinasty

  3. Seism nasty

  4. Autonomy

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Correct Option: A

The polar transport of auxin in stem segments in Volvos the movement of auxin from the.

movement in plants living world of plants - plant physiology biology

  1. Morphological apex towards the base

  2. Base towards the morphological apex

  3. Morphological apex towards the lateral

  4. Base towards the lateral branches

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Correct Option: A

'Touch me not' shows ..................... movement.

movement in plants living world of plants - plant physiology biology

  1. Nastic

  2. Tropic

  3. Both A and B

  4. None of the above

Show answer
Correct Option: A
Explanation:

  • Touch me not shows nastic movement.
  • Nastic movements are plant movements that occur in response to environmental stimuli. But unlike tropic movements, the direction of the response is not dependent on the direction of the stimulus. Some of the most spectacular plant movements are nastic movements. 
These include:
(i) The closing of 'Touch me not' plant in response to touch.
(ii) The closing of the carnivorous 'Venus Flytrap' leaf, when it captures prey or the folding of the Mimosa Pudica leaf, when it is disturbed.

Hence, option A is correct.

Mimosa plant shows seismonastic movement.

movement in plants living world of plants - plant physiology biology

  1. True

  2. False

Show answer
Correct Option: A
Explanation:
Seismonastic Movements: These movements are brought about by mechanical stimuli such as contact with a foreign body, fast wind and rain drops etc.  The leaves of Mimosa have the capability to display thigmonasty (touch-induced movement). In the sensitive plant, the leaves respond to being touched, shaken, heated or rapidly cooled. The speed of the response depends on the magnitude of the stimulus.

So, the correct answer is 'True'.

Bending of tentacles in Drosera is thigmonasty.

movement in plants living world of plants - plant physiology biology

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Drosera also known as Sundew is one of the largest carnivorous plants. They capture and digest insects which they eat to supplement the poor mineral nutrition that they obtain from the soil in which they grow. They bear glandular tentacles which they use in capturing prey. The tentacles being extremely sensitive bend towards the centre of the leaf so as to bring the insect close to their glands. Since this bending takes place in response to the touch brought about by the insect, it is a type of thigmonasty

Thus, the correct answer is option A. 

Match the answers correctly from codes given below.

   Movements    Stimuli
 A  Aerotaxis  I  Electric Potential
 B  Thermotaxis  II  Oxygen
 C  Rheotaxis  III  Heat
 D  Galvanotaxis  IV  Water
movement in plants living world of plants - plant physiology biology

  1. A-II, B-IV, C-III, D-I

  2. A-II, B-III, C-IV, D-I

  3. A-IV, B-I, C-II, D-III

  4. A-III, B-II, C-I, D-IV

Show answer
Correct Option: B
Explanation:

Aerotaxis - Movement of an organism, toward or away from air or oxygen.
Thermotaxis - Movement of an organism towards or away from a source of heat.
Rheotaxis - Movement of an organism in response to a current of water or air.
Galvanotaxis - a taxis in which a direct electric current is the orienting stimulus.

Match Column I with Column II and select the correct option from the codes given below.

Column I Column II
(a) Growth of pollen tube towards embryo sac (i) Thigmonasty
(b) Opening of flower (ii) Siesmonasty
(c) Turgor movement (iii) Epinasty
(d) Bending of tentacles of Drosera over the insect (iv) Chemotropism
movement in plants living world of plants - plant physiology biology

  1. a-(i), b-(ii), c-(iii), d-(iv)

  2. a-(iv), b-(iii), c-(ii), d-(i)

  3. a-(ii), b-(iii), c-(i), d-(iv)

  4. a-(iii), b-(iv), c-(ii), d-(i)

Show answer
Correct Option: B
Explanation:

Thigmonasty is the response of a plant to touch or vibration. In Drosera, tentacles bend towards the insect's direction after coming in contact. Seismonasty is a response to touch or blow. In Mimosa pudica, turgor movement is seen in leaflets in response to touch. Epinasty is the movement due to greater growth of the upper or inner surface. An example of epinasty is opening of flower and downward dropping of bud. Chemotropism is the response of a plant to chemical stimulus. An example of chemotropism is growth of pollen tube towards embryo sac due to presence of sugar in the style.

Thus, the correct answer is option B.