Tag: cytokinins, ethylene and abscisic acid

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Questions Related to cytokinins, ethylene and abscisic acid

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Which one of the following responses of plants to growth hormones is true for ethylene?

  1. Increase in cell elongation

  2. Decrease in the formation of female flowers

  3. Increase in ripening of fruits

  4. Decrease in abscission of flowers
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ethylene affects fruit - ripening. Normally, when the seeds are mature, ethylene production increases and builds - up within the fruit, resulting in a climacteric event just before seed dispersal. The nuclear protein 'Ethylene Insensitive 2' is regulated by ethylene production, and in turn, regulates other hormones including ABA and stress hormones.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Fruit ripening is accelerated by

  1. Warm surroundings

  2. Increased nitrogen supply

  3. Reduced water supply

  4. Ethylene rich atmosphere
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Ethylene is a plant hormone. It is also called as ripening hormone. It is responsible for ripening of fruits. Fruit ripening is accompanied by increased rate of respiration. Ethylene rich atmosphere is used to accelerate the process of ripening of fruits like banana.

Thus, the correct answer is option D.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Ethylene is mainly responsible for

  1. Formation of flower

  2. Formation of root hairs

  3. Ripening of fruits

  4. Formation of fruit
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

There are five classes of naturally occurring plant growth regulator. These are auxins, gibberellins, cytokinins, abscisic acid and ethylene. Ethylene is also called as ripening hormone as it is responsible for ripening of fruits. Fruit ripening is accompanied by increase rate of respiration. Due to increased respiration, complex carbohydrates are broken down into simpler sugars and cell wall becomes soft. It inhibits cell division. It is also involved in abscission of leaves, fruits and flowers.

Thus, the correct answer is option C.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Which response of growth hormone is true for ethylene?

  1. Decrease in flower abscission

  2. Decreases in femaleness

  3. Increase in fruit ripening

  4. Increase in cell elongation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ethylene is a gaseous plant hormone. It is also called as ripening hormone as it increases ripening of fruits. Fruit ripening is accompanied by increase rate of respiration. Due to increased respiration, complex carbohydrates are broken down into simpler sugars and cell wall becomes soft. It inhibits cell division. It is also involved in abscission of leaves, fruits and flowers.

Thus, the correct answer is option C.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Stomatal closing during full sunlight is best defined by

  1. Hormonal control
  2. $K^+$ion hypothesis
  3. $CO _2$ concentration

  4. Auxin effect
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Many hormone-like abscisic acid (for closing)  cytokinin (for opening) and ethylene (for opening and closing both) are responsible for opening and closing of stomata. 

So the correct option is 'Hormonal control'.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Seed dormancy is induced by

  1. ABA

  2. GA

  3. Thiourea

  4. Cytokinin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Abscisic acid is a plant hormone. It is also called as stress hormone. During unfavourable environmental conditions like drought, it induces seed dormancy. When there is favaourable condition, seed dormancy is broken and germination takes place.

Thus, the correct answer is option A.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

One hormone helps in ripening of fruits and other brings about stomatal closure. They are respectively

  1. ABA, IAA
  2. ${C} _{2}{H} _{4}$, ABA

  3. ABA, ehtylene
  4. ${C} _{2}{H} _{4}$, GA

  5. GA, ABA
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ethylene and abscisic acid both are the plant hormones. Ethylene hormone is also called as ripening hormone as it helps in the ripening of fruits. Abscisic acid is also called as a stress hormone. It promotes stomatal closure when insufficient water is available in the soil. 

Thus, the correct answer is option B.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Abscisic acid is called stress hormone as it 

  1. Induces flowering

  2. Breaks seed dormancy

  3. Promotes leaf fall

  4. Promotes stomatal closure
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Abscisic acid is a plant hormone. It is also called as stress hormone as under stress environmental condition, it induces seed dormancy. It promotes stomatal closure under water stress condition to decrease the rate of transpiration.

Thus, the correct answer is option D.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Which of the following is a correct statement?

  1. Negative geotropism in horizontal stems is caused by accumulation of auxin on the lower side.

  2. Pineapple can be made to flower in off season by the application of ethylene.

  3. The ratio of auxin to cytokinin controls cell differentiation.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Berry size of many seedless table grape cultivars can be substantially increased by applying gibberellic acid.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Which of the following is wrong about ethylene?

  1. Inhibit growth of root

  2. Ripening of fruits

  3. Elongation of stem in paddy

  4. Promote senescence of leaves & flowers
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Ethylene is a simple gaseous Plant growth hormone. It is synthesized in large amounts by tissues undergoing senescence and ripening fruits.
  • Ethylene promotes senescence and abscission of plant organs, especially of leaves and flowers.
  • Ethylene is highly effective in fruit ripening. It enhances the respiration rate during the ripening of the fruits. 
  • Ethylene promotes elongation of the stem in paddy.
  • Ethylene also promotes root growth and root hair formation, thus helping the plants to increase their absorption surface.
  • Hence Ethylene inhibits the growth of roots is a wrong statement about ethylene.
  • So, the incorrect option is 'Inhibit growth of root'.