Tag: chemical coordination in plants

Questions Related to chemical coordination in plants

The cut flowers and vegetables can be kept fresh a long period by this

plant hormone ...............

  1. Gibberellins

  2. Cytokinins

  3. Auxins

  4. Ethylene

  5. 2,4 - dichlorophenoxy acetic acid


Correct Option: B
Explanation:

Cytokinin is the plant hormone which is found to have profound effects in delaying the ageing of plant and thus increases the shelf life of vegtables and fruits. It acts by retarding the destruction and degeneration of chlorophyll and proteins. This is called as 'Richmond Lang effect'.

A plant hormone used for inducing morphogenesis in plant tissue culture

is ........................

  1. Abscisic acid

  2. Gibberellins

  3. Cytokinins

  4. Ethylene


Correct Option: C
Explanation:

Morphogenesis is the process of organ formation. Cytokinin is a plant hormone which plays a major role in organ formation or morphogenesis with the presence of auxin. It helps in rapid multiplication of cells by repeated cytokinesis and karyokinesis.

Cytokinesis refers to ................

  1. Division of chromosomes

  2. Division of cytoplasm

  3. Division of nucleus

  4. None of the above


Correct Option: B
Explanation:

Cytokinin is a plant hormone which is vital for the mitotic divisions taking place in plants. It thus enables cytokinesis and karyokinesis in the cells. This makes cytokinin an important constituent in callus culture.

Cytokinins are mostly produced in

  1. Shoot apex

  2. Root apex

  3. Young leaves

  4. Lateral buds


Correct Option: B
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. When an excised leaf is induced to root, it does not turn yellow because root apex synthesizes cytokinin hormone.

Thus, the correct answer is option B.

Delay in senescence is caused by the spray of 

  1. IBA

  2. GA

  3. Cytokinin

  4. ABA


Correct Option: C
Explanation:

Senescence means aging. Cytokinin is a plant hormone. It plays major role in cell proliferation and cell division. 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. 

Thus, the correct answer is option C.

Cytokinins are generally

  1. Acids

  2. Aminopurines

  3. Phenols

  4. Glucosides


Correct Option: B
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 option B.

Cell mitosis is induced by

  1. Colchicine

  2. Gibberellic acid

  3. Nitrosoguanidine

  4. Kinetin


Correct Option: D
Explanation:

Kinetin is a type of cytokinin which is a plant hormone. It promotes cell division. It induces the cell mitosis by maintaining the protein like cyclins and CDKS that are important for mitosis. 

Thus, the correct answer is option D.

Kinetin like properties are present in

  1. Pineapple

  2. Soyabean

  3. Groundnut

  4. Coconut milk


Correct Option: D
Explanation:

Kinetin is a type of cytokinin which is a plant hormone. It promotes cell division. The first known cytokinin hormone was found in coconut milk. Coconut milk is liquid endosperm. It promotes cell division same as kinetin. It stimulates the embryo to grow when it is supplied with food.

Thus, the correct answer is option D.

Flowering in some short day plants is promoted by

  1. Auxins

  2. Gibberellins

  3. Cytokinins/ABA

  4. Ethylene


Correct Option: B
Explanation:

Gibberellin is a plant hormone which helps in growth of stem. The rapid growth and flowering with cell division and cell elongation is called as bolting. Bolting requires either long days or cold treatment. Bolting can be induced by higher level of gibberellin under normal conditions. Hence, it induces flowering in some short day plants.

Thus, the correct answer is option B.

Cytokinins have the ability to

  1. Induce morphogenesis

  2. Substitute cold treatment

  3. Convert dwarf plants to tall plants

  4. None of the above


Correct Option: A
Explanation:

Cytokinins are plant hormones that are involved in various physiological processes. They promotes cell division by stimulating mitosis. Due to increased rate of mitosis, they induce shoot and root morphogenesis. They also plays important role in formation of fruits and seeds.

Thus, the correct answer is option A.