Tag: movement in plants

Questions Related to movement in plants

Movements of trichomes in Drosera are

  1. Photonastic

  2. Thermonastic

  3. Thigmonastic

  4. Seismonastic


Correct Option: C
Explanation:

Thigmonastic movements occur in some plants in response to tactile stimuli. The movements may be defensive or offensive-response to the touch of an herbivore interested in ingesting the plant or by contrast, in response to the touch of an insect that may serve as a potential meal for a carnivorous plant.

Jerky lateral leaflet movements of Desmodium gyrans are

  1. Negative geotropic movements

  2. Positive geotropic movements

  3. Hydrotropic movements

  4. None of the above


Correct Option: D
Explanation:
Desmodium gyrans is well known as the 'telegraph plant' and famous for its movement. The small lateral leaflets will rotate on their axis, moving in jerky motions under the slightest influence of touch, sunshine, warmth or small vibrations. At night they droop downwards
So, the correct answer is 'None of the above'

Plant movement in response to diffuse stimulus of light is

  1. Phototropism

  2. Photolysis

  3. Phototaxis

  4. Photonasty


Correct Option: C
Explanation:

Phototaxis - is a kind of taxis or locomotory movement, that occurs when a whole organism moves towards or away from stimulus of light. It is called positive if the movement is in the direction of increasing light intensity and negative if the direction is opposite
So, the correct answer is 'Phototaxis'

Grasses fold their leaves due to 

  1. Bulliform cells

  2. Stomata

  3. Hydathodes

  4. Transfusion tissue


Correct Option: A

Stimulus for flowering accepted by 

  1. Young leaves

  2. Mature leaves

  3. Stem tissues

  4. None of the above


Correct Option: A
Explanation:

Stimulus for flowering will be accepted by young leaves. Apart from light and chemical stimulus for flowering, temperature is also one important stimulus that a lot of plant species use to flower, e.g., some orchid species.

Opening of a flower and drooping of a bud are examples of 

  1. Nyctinasty

  2. Hyponasty

  3. Seismonasty

  4. Movement of curvature

  5. Epinasty


Correct Option: E
Explanation:

Opening of a bud and drooping of bud are called as epinastic movements. It is well defined as the increased growth of the upper surface of a plant part, such as leaf, resulting in a downward bending of the part.

Shock movement in Touch me not plant is

  1. Seismonasty

  2. Photonasty

  3. Chemonasty

  4. Thermonasty


Correct Option: A
Explanation:

Seismonasty or thigmonasty is the nastic movement induced in plants where the stimulus is touch. Touch-me-not plant, which has the scientific name as Mimosa pudica is sensitive to touch and is thus called as seismonastic.

Which type of trophism is shown by tulip and sunflower respectively?

  1. Thigmonasty and photonasty

  2. Hydronasty and thermonasty

  3. Thermonasty and photonasty

  4. Hydronasty and photonasty


Correct Option: C
Explanation:

The flowers of sunflower open in the morning which is an example of photonasty (regulated by light). Tulip flowers open at high temperature, example of thermonasty (regulated by temperature).

Opening of flowers involves

  1. Epinasty

  2. Hyponasty

  3. Nutation

  4. Phototaxis


Correct Option: A
Explanation:

Nastic movements are responses of plant parts to stimuli. Epinasty is the downward bending of a leaf resulting from greater growth of the upper side than of the lower side. Due to more growth on the upper side, the flower will open due to epinasty. The hyponasty is an upward bending of leaves resulting from greater growth of the lower side. Nutation is the bending movements shown by some plant parts due to the unequal rate of growth of different parts of plants. Movement of plant in response to light is called as phototaxis.

Thus, the correct answer is option A.

Plant movements unrelated to external stimulus are

  1. Autonomic

  2. Paratonic

  3. Mechanical

  4. Hygroscopic


Correct Option: A
Explanation:

Autonomic movement is the spontaneous movement of the protoplasm seen in aquatic plants due to internal stimulus. It is not related to the external stimulus. Movement of cilia and flagella is an example of autonomic movement. A movement shown by a plant part in response to an external factor is called as paratonic movement. In this, the direction of movement is controlled by the direction of the stimulus. Mechanical movements are seen by non-living organs of plants due to hygroscopic changes.

Thus, the correct answer is option A.