Tag: seed dormancy

Quizzes (0) Questions (41)

Questions Related to seed dormancy

Multiple choice biology plant growth seed dormancy fruit plants: structure and function

The cause of dormancy for sometime in fertilized ovule is 

  1. Presence of Auxin hormone

  2. Zygote divides only after certain amount of endosperm is formed

  3. Presence of growth inhibitor ABA

  4. Presence of least amount of water
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The fertilized ovule is got dormant so that the adequate amount of endosperm is formed as for division and for further survival, it is very necessary that ample amount of food is present in the seed.

So the correct option is 'Zygote divides only after a certain amount of endosperm is formed'.

Multiple choice biology plant growth seed dormancy fruit plants: structure and function

Which of the following breaks the dormancy of potato tubes?

  1. IAA

  2. ABA

  3. Zeatin

  4. Gibberellin
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Dormancy of seeds could be broken by the activation of digestive enzymes like alpha amylases. It is being done by phytohormones like gibberellic acid. It also helps in cell elongation, division of lateral meristem and many more.

Multiple choice biology plant growth seed dormancy fruit plants: structure and function

Seed dormancy is due to the : -

  1. Ethylene

  2. Abscissic acid

  3. IAA

  4. Starch
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Seed dormancy is defined as a state in which seeds are prevented from germinating even under environmental conditions normally favorable for germination. The sesquiterpene abscisic acid (ABA) regulates many processes during the plant life cycle, including key events during seed formation, such as the deposition of storage reserves, prevention of precocious germination, the acquisition of desiccation tolerance, and the induction of primary dormancy.

So, the correct answer is 'Abscissic acid'.
Multiple choice biology plant growth seed dormancy fruit plants: structure and function

Which of the following is used to break the seed dormancy?

  1. ABA

  2. Cytokinin

  3. Auxin

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

ABA, abscisic acid was discovered for its role in regulating abscission and dormancy. It acts as a general plant growth inhibitor and an inhibitor of plant metabolism. It inhibits seed germination, stimulates the closure of stomata in the epidermis and increases the tolerance of the plant to various kind of stresses. 

Gibberellins cause fruits like apple to elongate and improve its shape. They also delay senescence.
Auxins promote stem elongation, inhibit the growth of lateral buds (maintains apical dominance). They are produced in the stem, buds, and root tips. Ethylene is highly effective in fruit-ripening, it promotes senescence and abscission of plant organs especially leaves and flowers. Ethylene breaks the seed and bud dormancy and initiates seed germination.

Multiple choice biology plant growth seed dormancy fruit plants: structure and function

Dormancy of seed is broken by 

  1. Auxin

  2. Gibberellin

  3. Abscisic acid

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

Gibberellin are involved in seed germination in certain plants. They break seed dormancy by promoting mobilisation of reserve food material. In a classic experiment involving barley seed germination, researchers showed that the release of gibberellin from the embryo triggers the synthesis of $\alpha$-amylase, an enzyme that digests starch in the endosperm. As a result, glucose becomes available for absorption by the embryo. Although enzymes mobilize starch reserves in many types of seeds, gibberellin control of seed enzymes appears restricted to cereals and other grasses. 

Thus, the correct answer is option B.

Multiple choice biology plant growth seed dormancy fruit plants: structure and function

Type of seed dormancy is

  1. Physiological

  2. Morphological

  3. Mechanical

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

The conditions present outside the embryo causes Exogenous dormancy and are grouped into physiological, morphological and mechanical dormancy.

So the correct option is 'All of the above.'

Multiple choice biology plants: structure and function seed dormancy fruit plant growth

Seed dormancy is an adaptation to ensure its germination during

  1. Unfavourable period

  2. Favourable period

  3. Stress condition

  4. Dessication
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Seed dormancy is an adaptation to ensure its germination during favourable period. One important function of most seeds is delayed germination, which allows time for dispersal and prevents germination of all the seeds at the same time. The staggering of germination safeguards some seeds and seedlings from suffering damage or death from short periods of bad weather or from transient herbivores; it also allows some seeds to germinate when competition from other plants for light and water might be less intense. Seed dormancy can be caused by all the factors mentioned. A dormant seed is one that is unable to germinate in a specified period of time under a combination of environmental factors that are normally suitable for the germination of the non-dormant seed. Dormancy is a mechanism to prevent germination during unsuitable ecological conditions, when the probability of seedling survival is low. 
Thus, the correct answer is option B.

Multiple choice biology plant growth seed dormancy fruit plants: structure and function

Select the correct reason for seed dormancy.

  1. Immature embryo

  2. Hard seed coat

  3. Presence of germinating inhibitors

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

Dormancy is the condition of a seed when it fails to germinate even when environmental conditions considered necessary for germination are available. The following are some main causes of seed dormancy:

1) Immature embryo: some seeds fail to germinate due to the partial development of the embryo at the time of their dissemination.
2) Hard seed coat: the presence of hard seed coat causes dormancy as it is impermeable to water and gases and mechanically restrict the growth of the embryo.
3) The presence of germinating inhibitors: Some plants produce certain chemical compounds which inhibit seed germination.
Thus option D is the correct answer.