Tag: biology

Questions Related to biology

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.

The closure of the lid of pitcher in pitcher plant is

movement in plants living world of plants - plant physiology biology

  1. A paratonic movement

  2. A tropic movement

  3. A turgor movement

  4. An autonomous movement

Show answer
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

movement in plants living world of plants - plant physiology biology

  1. Thermonasty

  2. Seismonasty

  3. Photonasty

  4. Nyctinasty

Show answer
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

movement in plants living world of plants - plant physiology biology

  1. Auxin

  2. Hormone

  3. Alcohol

  4. None of the above

Show answer
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

movement in plants living world of plants - plant physiology biology

  1. Autonomic movements of variation

  2. Autonomic movements of growth

  3. Paratonic movements of variation

  4. Paratonic movements of growth

Show answer
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.

Some flowers (e.g., Oxalis) open in the morning and close during evening because of

movement in plants living world of plants - plant physiology biology

  1. Photonasty

  2. Phototropism

  3. Phototaxis

  4. Nyctinasty

Show answer
Correct Option: A
Explanation:

Nastic movements are responses of plant parts to stimuli. Photonastic movement is the nastic response of plant in response to light. Oxalis flowers open in the morning and close during evening because of photonasty. Phototropism is the growth of a plant part in response to light. Phototaxis is the movement of a plant part in response to light. Nyctinasty is the rhythmic nastic movement of plant in response to the onset of darkness. 

Thus, the correct answer is 'Photonasty'

Which of the following pair is proper for plant movement?

movement in plants living world of plants - plant physiology biology

  1. Thermotaxis - Chlamydomonas

  2. Thigmotaxis - Zoospore in Oedogonium

  3. Rotation movement - Cytoplasm in Tradeschantia anther

  4. Chemotaxis - Zoospore of Volvox

Show answer
Correct Option: B
Explanation:

Movement of plant in response to heat is called as thermotaxis. Movement of plant in response to a touch stimulus is called as thigmotaxis. Example include zoospore in Oedogonium. Movement of plant in response to external chemical is called as chemotaxis. Movement of plant in response to light is called as phototaxis. Chlamydomonas shows phototactic movement. 

Thus, the correct answer is 'Thigmotaxis - Zoospore in Oedogonium.'

Which locomotory movement is not correct?

movement in plants living world of plants - plant physiology biology

  1. Cyclosis and rotation of cytoplasm in Hydrilla

  2. Sucrose induced movement of sperms

  3. Flagellar movement of slime mould

  4. Chlamydomonas moves away from intense light

Show answer
Correct Option: D
Explanation:

Cyclosis is also called as cytoplasmic streaming. It is the directed movement of cytosol and organelles. Rotational cyclosis is seen in Hydrilla. Sperm movement is induced by the change in intracellular ion concentration. Sperm motility is also induced by sucrose. Flagella is a locomotory organ that is seen in slime mould along with fungi, protozoan, etc. Slime mould shows flagellar movement. Chlamydomonas move towards the light.

Thus, the correct answer is option D.

Opening of floral buds is

movement in plants living world of plants - plant physiology biology

  1. Autonomic movement of variation

  2. Paratonic movement of growth

  3. Autonomic movement of growth

  4. Autonomic movement of locomotion

Show answer
Correct Option: C
Explanation:
Opening of floral buds into flower is a type autonomic movement of growth. It is a nastic movement. Nastic movement is a non-directional movement shown by plant part in response to external stimuli. Greater growth on one side results in the bending on the opposite side. 
Thus, the correct answer is option C.

Thigmonastic movement is found in

movement in plants living world of plants - plant physiology biology

  1. Albizzia

  2. Oxalis

  3. Drosera

  4. Nepenthes

Show answer
Correct Option: A
Explanation:

Thigmonastic movement is the nastic or nondirectional movement shown by plant part in response to the touch or vibration. Plants like Mimosa and Albizzia shows thigmonastic movement. Oxalis shows photonastic movement. Drosera shows haptonastic movement. 

Thus, the correct answer is 'Albizzia'.