Tag: seed dormancy

Questions Related to seed dormancy

Embryo are not differentiated into different tissues at the time of fruit ripening. Select option related to this statement?

  1. Endogenous dormancy, morphological dormancy

  2. Exogenous dormancy, physiological dormancy

  3. Exogenous dormancy, morphological dormancy

  4. Endogenous dormancy, mechanical dormancy


Correct Option: A
Explanation:
The dormancy caused by conditions within the embryo itself is called endogenous dormancy. It includes physiological dormancy, morphological dormancy, and combined dormancy, Morphological dormancy is a type of endogenous dormancy. In this, the embryo is underdeveloped or undifferentiated. Thus, the correct option is A.

Most of the phosphorus in the developing seeds is stored as.

  1. Ergastic substances

  2. Phosphate

  3. Nucleic acid

  4. Phytic acid


Correct Option: A

For a seed to germinate, the dormancy period will need to be broken by 

  1. Warmth

  2. Water

  3. Air

  4. Both A and B


Correct Option: D
Explanation:

Dormancy period is an inactive state of seed. To break down this state, seed require the favourable environment in which temperature and water play a major role to increase the metabolism as enzymes work on certain temperature and water breaks the seed coat by imbibition.

So the correct option is 'Both A and B'.

Which one does not exhibit seed dormancy?

  1. Phaseolus

  2. Rhizophora

  3. Cassia

  4. Xanthium


Correct Option: B
Explanation:

As a viviparous plant, Rhizophora creates a propagule that is in reality a living tree. Though resembling an elongated seed pod, the fully-grown propagule on the mangrove is capable of rooting and producing a new tree. The trees are hermaphrodites, capable of self pollination or wind pollination. The tree undergoes no dormant stage as a seed, but rather progresses to a live plant before leaving its parent tree. A mangrove propagule may float in brackish water for over a year before rooting. So, the correct answer is 'Rhizophora'.

Which of the following is not the example of escape in time?

  1. Seed dormancy

  2. Arctic tern

  3. Diapause

  4. Hibernation


Correct Option: B

Dormancy is absent in seeds of ______________.

  1. Wheat

  2. Maize

  3. Rhizophora

  4. Cycas


Correct Option: A

Which of the following action makes a seed coat becomes permeable to water?

  1. Scarification

  2. Stratification

  3. Vernalization

  4. All of the above


Correct Option: A
Explanation:

Scarification involves weakening, opening or altering the coat of a seed to encourage the germination. It can be done mechanically, thermally and chemically. This will make the seed coat permeable for water and air, which will help in germination of seeds.

Stratification is the process of pretreating the seed to stimulate natural condition that a seed must endure before germination. It involves soaking and chilling of seeds prior to sowing.
Vernalisation is the induction of plant's flowering process by exposure to the prolonged cold of winter. It literally has to be chilled in order to reproduce.
Somewhere, all these processes are used to break the dormancy the seeds naturally as well as artificially
So, the correct answer is 'Scarification'

Which of the following conditions is needed by almost all seeds to break dormancy?

  1. Exposure to light

  2. lmbibition

  3. Abrasion of the seed coat

  4. Exposure to cold temperatures


Correct Option: B
Explanation:

Seed dormancy allows seeds to overcome periods that are unfavourable for seedling established and is therefore important for plant ecology and agriculture. Several processes are known to be involved in the induction of dormancy and in the switch from the dormant to the terminating state. Imbibition is a special type of diffusion when water is absorbed by solids-colloids causing an enormous increase in volume. If it were not for the pressure due to imbibition, seedlings would not have been able to emerge out of the soil into the open; they probably would not have been able to establish.

So the correct option is 'Imbibition'.

State whether the following statements are true or false.
In a plant seedling exposed to light on only one side, auxin produced in the tip moves to the lighted side and inhibits growth of cells there.

  1. True

  2. False


Correct Option: B
Explanation:

When the light is exposed to only one side of the seedling, the auxin will move and grow towards the side of the light. This phenomenon is termed as phototropism (Movement of plant growth towards the source of light). Thus only one seed of the seedling will be able to grow and the other where light is unable to reach will not grow.

So, the correct statement is 'False'.

Seed dormancy is associated with

  1. Hard seed coat

  2. Immature embryo

  3. Presence of germination inhibitors

  4. All of these


Correct Option: D
Explanation:
Seed dormancy is defined as a state in which seeds are prevented from germinating even under environmental conditions normally favourable for germination. There are a few main causes of seed dormancy, such as hard seed coat, which are impermeable to water and gases so restrict water uptake and oxygen exchange. The immature embryo that is seeded with small and undeveloped embryos do not germinate. Germination inhibitors that is Seeds contain some chemical plant growth regulators, which inhibit seed germination.
So, the correct option is, 'all of these'.