Which plant hormone helps in breaking the dormancy of plant?

Which plant hormone helps in breaking the dormancy of plant?

A. Auxin

B. Gibberellin

C. Cytokinin

D. Ethylene

Answer: Gibberellin

What is Dormancy?

Dormancy is a completely natural cycle that some seeds and bulbs go through. As a plant prepares for winter, it carefully stores away food and water in a seed or bulb. This food and water will help it grow again when the right conditions return the following spring – whether after a week, a month, or several months! A dormancy period can be broken by various things that happen in an environment. A good example of this is provided by the way that deciduous trees lose their leaves during winter – they entering a state of dormancy.

Dormancy of Plant

Dormancy is a state in which energy and metabolic requirements of the plant are very low and growth and development stop. Plant dormancy can be induced by environmental or genetic factors, but the basic underlying physiological mechanisms are conserved among species. This review focuses on recent progress in understanding the molecular basis of dormancy in plants, especially in seeds.

Breaking the Dormancy of Plant

The seed dormancy phenomenon is encountered in many economically important plant species and often limits the successful establishment of crops. We propose that during dormancy, the status of the embryo and interaction between the embryo and seed coat regulates germination. Breaking dormancy involves a change in the embryo’s tissue water content, pH, and/or osmotic potential, which may be associated with changes in cell membrane permeability. The breaking can be readily detected according to changes in plasma membrane structure and/or conductance measured by impedance spectroscopy.

What are Auxins?

Auxins are plant hormones that regulate growth. Auxins also play a role in cell division and differentiation, in fruit development, in the formation of roots from cuttings, in the inhibition of lateral branching (apical dominance), and in leaf fall (abscission). Auxins are abundantly produced in meristematic region of the shoot. Auxins were discovered by botanist Fritz W. Went.

What are the functions of Auxins?

Auxin is a plant hormone that helps control the growth of plants. Auxin promotes cell growth and elongation of the plant. In the elongation process, auxin alters the plant wall plasticity making it easier for the plant to grow upwards. Auxins are responsible for rooting formations.

What are Gibberellins?

Gibberellins are plant hormones that regulate various developmental processes, including stem elongation, germination, dormancy, flowering, flower development, and leaf and fruit senescence. GAs are one of the longest-known classes of plant hormone.

What are the functions of Gibberellins?

Gibberellins are the most important plant growth regulators. These hormones function by increasing the rate of various developmental processes, hence they are called “Growth promoting substances”. Gibberellins act by stimulating cell elongation of different plant organs, especially stems. They also cause broadening of epidermal cells (leaf cells). Gibberellins enhance the development of fruit and induce the formation of seeds.

What are Cytokinins?

Cytokinins are naturally occurring plant growth regulators, eliciting responses necessary for normal growth and development. Cytokinins are involved in cell division, leaf senescence, apical dominance, shoot initiation and growth, phyllotaxis, vascular, gametophyte and embryonic development. They also mediate the response to biotic and abiotic factors such as light intensity and mechanical stress.

What is the function of cytokinin?

The function of cytokinin in plants is to control the division of cells. This hormone helps in increasing the cell’s growth, development, differentiation, affecting apical dominance, leaf senescence, and axillary bud growth. Cytokinins also promote seed germination and root cell division. The addition of cytokinin in plant’s leaves increase transpiration which increases water loss. It is popularly known as plant growth stimulating hormone.

What is an example of cytokinin?

The most abundant cytokinin in Arabidopsis is trans-zeatin. Kinetin is an artificial, aromatic cytokinin and benzyladenine is an example of a naturally occurring aromatic cytokinin. Thidiazuron is a diphenylurea-type cytokinin.

What is Ethylene?

Ethylene is a natural plant hormone that basically stimulates the growth and senescence. Ethylene is a colorless flammable gas with a faint “sweet and musky” odor when pure. Ethylene is the simplest alkene. Ethylene is widely used in the chemical industry, and its worldwide production exceeds that of any other organic compound.

What is the function of Ethylene?

Ethylene is a hormone that promotes growth and senescence processes depending on its concentration, timing of application, and the plant species.

Plant Growth and Development MCQs and Answers –Set-1

1. Which plant hormone helps in breaking the dormancy of plant?

2. Which hormone is formed in leaves and helps in the blooming of the flowers?

3. Which plant hormone is formed in injured cells by which the injury of plant is healed?

4. Which of the following hormone help in the cell division and development in the presence of auxins?

5. Name the plant hormone which increases the activity of cambium in the wooden plants?

6. Growth regulators, which control plant growth and development are called___________

7. Growth in plants is mainly driven by turgor pressure.

8. Which of the following is NOT a plant hormone?

9. Name the plant in which auxin was first discovered?

10. Which of the following is NOT a naturally occurring auxin?

Plant Growth and Development NEET MCQ –Set-2

1. Uneven distribution of auxins may lead to

2. Tendrils of garden peas coiling around any support signifies:

3. ____________ tissues synthesize natural cytokinins

4. ________ is a plant hormone generally present in the gaseous state

5. _________ is a colourless gas that serves as a signalling hormone.

6. Which plant hormone is responsible for saving the crops from falling.

7. Which of the following hormone is found in gaseous form?

8. Name the plant hormone which is responsible for the ripening of fruits?

9. Which plant hormone is helpful in making RNA and protein?

10. Which of the following statement is incorrect?

Important Questions on Plant Growth and Development –Set-3

1. The term auxin was coined by

2. Precursor of Indole acetic acid (natural auxin) is

3. All the following hormones are growth inhibitors except

4. Which of the following is a gaseous hormone

5. Which of the following bioassays are used to detect the presence of auxin

6. Coconut milk contains a cytokinin called ____ which promotes plant growth.

7. One of the following is not an auxin

8. _________can stimulate the germination of barley seeds

9. Seed dormancy is triggered by

10. The significance of the day length in plants was first shown in:

Plant Growth and Development NEET Questions –Set-4

1. A seed which is just waiting for favourable environmental condition to germinate is called

2. Richmond – Lang effect is

3. 2,4-D is used as

4. The type of germination in which cotyledons come above the ground is called as

5. In most of monocot plants, germination is

6. The phase of growth which is the first phase and represents lag phase of growth curve is

7. The lateral meristem in plant is responsible for

8. Plant growth can be measured by

9. Auxins were first isolated form the plants by

10. Apical dominance is due to

Plant Growth and Development Short Questions for NEET –Set-5

1. Identify the true statement/statements regarding growth and development in organisms.

2. Vernalization treatment can convert

3. Scarification is a method of overcoming dormancy in seeds which

4. Identify the precursor substance used in the biosynthesis of gibberellins in plants.

5. Seeds in which germination is stimulated by light are called

6. The chemical substances like phenolics, caumarins, ferulic acid are

7. The seeds which can not germinate in absence of light is called

8. Germination inhibitors leached out by one plant may inhibit germination of seeds of other plants is called as

9. The dormancy of seed is due to mechanical resistance of seed coat in

10. Which of the following growth harmones in plant is influenced by light?

Plant Growth and Development Class 11 questions and answers –Set-6

1. Name the amino acid which acts as a precursor of auxin biosynthesis?

2. Mark the one, which is NOT a physiological effect of auxin?

3. Name the site of Gibberellins synthesis

4. Gibberellin that is synthesized in the shoot transported to different parts of the plant by which medium?

5. What is bolting?

6. Which of the following plant hormone is responsible for seed germination?

7. Name the first naturally occurring cytokines.

8. Which of the following plant hormone causes a delay in leaf senescence?

9. Name the stress hormone of the plant.

10. Deficiency in which of the following hormone causes dwarfism in the plant?

Plant Growth and Development objective questions and Answers –Set-7

1. Who classified the plants into different categories on the basis of photoperiodic responses

2. The plant which needs light period shorter than critical period is called

3. Vernalization is also called as

4. The harmone which stimulates the flowering in vernalized plant is

5. Vernalization is

6. Epigeal germination is found in

7. Which of the following substance acts as natural germination inhibitor?

8. The part of seed which emerges out first during germination is

9. Indefinite growth of plants is due to presence of

10. In which of the following, rate of growth gradually slows down and comes to steady stage?