Questions Related to biology

Multiple choice biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

The regulator which retards ageing senescence of plant parts is

  1. Cytokinin

  2. Auxin

  3. Gibberellin

  4. Abscisic acid

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cytokinins is a plant hormone. It retards ageing senescence of plant parts and thus keep them productive for longer duration. This is called as Richmond Lang effect. It delays destruction of chlorophyll. It has an effect on protein synthesis and mobilizing nutrients. 

Thus, the correct answer is option A.

Multiple choice biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

Cytokinins are mostly

  1. Glucosides

  2. Aminopurines

  3. Acidic

  4. Phenolic

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The first cytokinin discovered was an aminopurine derivative named kinetin. Except zeatin which is adenine derivative, all other present cytokinins are aminopurines. All the naturally occurring cytokinins are substituted purines, in which sixth carbon is substituted by amino group.

Thus, the correct answer is 'Glucosides'.

Multiple choice biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

Hormone discovered through tissue culture technique is

  1. Auxin

  2. Cytokinin

  3. Gibberellin

  4. Abscisic acid

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hormone discovered through tissue culture technique is cytokinin. Cytokinin was discovered by Skoog and Miller. The first cytokinin discovered was kinetin. This was isolated as a DNA degradation product. 

Thus, the correct answer is option B.

Multiple choice biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

Hormone that promotes growth of lateral buds/has negative effect on apical dominance is

  1. Cytokinin

  2. Gibberellin

  3. Auxin

  4. Both B and C

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Apical dominance is a phenomenon in which central stem is dominant and lateral stems are suppressed. It is due to plant hormones auxin produced in the tip of the shoot. It promotes apical dominance and does not allow lateral / axillar buds to grow. Another plant hormone, cytokinin is responsible for having negative effect on the apical dominance. It promotes the growth of lateral buds.  

So, the correct answer is 'Cytokinin'

Multiple choice biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

Interfascicular cambium formation is induced by

  1. Auxin

  2. Cytokinin

  3. Gibberellin

  4. Ethylene

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cytokinin is a plant hormone which is involved in growth and development of plants. It is required for the cambial growth. Kinetin, a type of cytokinin promotes cell division. It induces formation of interfascicular cambium in plants.

Thus, the correct answer is option B.

Multiple choice biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

Cytokinin synthesis is maximum in

  1. Roots

  2. Leaves

  3. Shoot tip

  4. Fruit

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cytokinin is a plant hormone. It promotes cell division. It also delays the destruction of chlorophyll and protein. It shows delay of senescence in leaves. It is mostly produced in the root apex. Roots synthesize maximum amount of cytokinin hormone.

Thus, the correct answer is 'Roots'.

Multiple choice biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

Which of the following is a cytokinin?

  1. Phytochrome

  2. Leucine

  3. Ethylene

  4. Zeatin

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cytokinin is a plant hormone which is involved in various physiological processes of plants. Zeatin is the most common type of naturally occurring cytokinin. It is found in maize. It is also found in the coconut milk. It promotes cell division.

Thus, the correct answer is option D.

Multiple choice biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

Induction of cell division and delay in senescence are due to

  1. Gibberellin

  2. Auxin

  3. Cytokinin

  4. Ethylene

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cytokinin is a plant hormone. It plays major role in cell proliferation and cell division. It also delays the destruction of chlorophyll and protein. During senescence, cytokinin levels are low. It delays in senescence of leaves when sprayed externally by delaying the destruction of chlorophyll and proteins in leaves

So, the correct answer is 'Cytokinin'

Multiple choice biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

Which is not a function of cytokinin?

  1. Delay is senescence

  2. Breaking seed dormancy

  3. Promoting bud dormancy

  4. Promoting stomatal opening

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cytokinin (CK) is a plant hormone. It promotes cell division and delays senescence in plants. It improves nutrient mobilization and thus delays leaf senescence. When applied externally, it mobilizes nutrients towards sites of application. It also promotes stomatal opening along with auxin hormone. It also breaks the dormancy of seeds and induce seed germination. 

Thus, the correct answer is option C.