Tag: movement in plants

Questions Related to movement in plants

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

  1. Morphological apex towards the base

  2. Base towards the morphological apex

  3. Morphological apex towards the lateral

  4. Base towards the lateral branches


Correct Option: A

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

  1. Nastic

  2. Tropic

  3. Both A and B

  4. None of the above


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.

  1. True

  2. False


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.

  1. True

  2. False


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
  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


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
  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)


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.

The closure of the lid of pitcher in pitcher plant is

  1. A paratonic movement

  2. A tropic movement

  3. A turgor movement

  4. An autonomous movement


Correct Option: A
Explanation:
Paratonic movements are some plants movements which are caused in response to certain stimuli and are said to be induced or plant movements which take place spontaneously , without any irritability or sensitivity of the protoplasm. Paratonic movements are of three kinds-Tropic, Tactic and Nastic movements. Tactic movements are movements of locomotion, which are induced by some unidirectional external stimuli. These directions are controlled by the direction of the stimulus. Depending upon the nature of the stimuli, these movements are of the following types- Phototactic, Chemotactic and Thermotactic. 
Pitcher plant are type of carnivorous plants. Foraging, flying or crawling insects such as flies are attracted to the cavity formed by the cupped leaf, often by the visual lures such as anthrocyanin pigments and nectar bribes. The rim of the pitcher is slippery when moistened by the condensation or nectares caused by insects falling into the trap. 

Movements of leaves of the sensitive plant Mimosa pudica is due to

  1. Thermonasty

  2. Seismonasty

  3. Photonasty

  4. Nyctinasty


Correct Option: B
Explanation:
A response of a plant that causes movement independent of the direction of the stimulus is a nastic response. It is not a growth response. This type of response is reversible and can be repeated many times. Seismonasty is a nastic movement in response to shock.When the leaflets are touched, there is rapid folding of the leaflets of the sensitive plant due to changes in turgor pressure. Mimosa pudica is known as touch me not plant for this feature.
Thus, the correct answer is option B. 

Stimulus in Mimosa pudica travels in the form of

  1. Auxin

  2. Hormone

  3. Alcohol

  4. None of the above


Correct Option: B
Explanation:

The dropping of leaves of Mimosa pudica shows thigmonastic movement upon touching. This dropping is due to the action potential which travels through the plant. The stimulus travels in the form of signaling molecules and hormones. These includes intracellular calcium, reactive oxygen species, ethylene hormone.

So, the correct answer is B 'Hormone'

Desmodium gyrans shows

  1. Autonomic movements of variation

  2. Autonomic movements of growth

  3. Paratonic movements of variation

  4. Paratonic movements of growth


Correct Option: A
Explanation:

Autonomic movement is the spontaneous movement of the protoplasm due to internal stimulus. Autonomic movement of variation takes place due to changes in the turgidity of cells. The leaves of Desmodium gyrans shows jerky lateral movement due to turgor change which results in the alteration of osmotic content. A movement shown by a plant part in response to an external factor is called as paratonic movement. 

Thus, the correct answer is option A.