Tag: plant growth

Questions Related to plant growth

Which one does not exhibit seed dormancy?

biology plant growth seed dormancy fruit plants: structure and function

  1. Phaseolus

  2. Rhizophora

  3. Cassia

  4. Xanthium

Show answer
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?

biology plant growth seed dormancy fruit plants: structure and function

  1. Seed dormancy

  2. Arctic tern

  3. Diapause

  4. Hibernation

Show answer
Correct Option: B

Dormancy is absent in seeds of ______________.

biology plant growth seed dormancy fruit plants: structure and function

  1. Wheat

  2. Maize

  3. Rhizophora

  4. Cycas

Show answer
Correct Option: A

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

biology plant growth seed dormancy fruit plants: structure and function

  1. Scarification

  2. Stratification

  3. Vernalization

  4. All of the above

Show answer
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?

biology plant growth seed dormancy fruit plants: structure and function

  1. Exposure to light

  2. lmbibition

  3. Abrasion of the seed coat

  4. Exposure to cold temperatures

Show answer
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.

biology plant growth seed dormancy fruit plants: structure and function

  1. True

  2. False

Show answer
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

biology plant growth seed dormancy fruit plants: structure and function

  1. Hard seed coat

  2. Immature embryo

  3. Presence of germination inhibitors

  4. All of these

Show answer
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'.

Seed dormancy can be broken by the following combination of chemicals

biology plant growth seed dormancy fruit plants: structure and function

  1. ${GA} _{3}$, IAA, ABA

  2. $KN{O} _{3}$, ${GA} _{3}$ and ethylene chlorohydrin

  3. NAA, 2, 4, 5-T and IAA

  4. ABA, BAP and ${GA} _{3}$

Show answer
Correct Option: B
Explanation:

Seed dormancy is induced in plants under unfavorable condition due to growth inhibitor hormone-like abscisic acid. Gibberellin is most commonly used to breaks the seed dormancy and induce flowering under normal condition. Apart from this, other chemicals are used to break the seed dormancy. These chemicals include potassium nitrate (KNO$ _3$), thiourea and ethylene chlorhydrin.

Thus, the correct answer is option B.

Vernalization can remove Kernel wrinkles in:

vernalisation plant growth growth and development plant growth and development biology

  1. Wheat

  2. Petkus rye

  3. Maize

  4. Rice

Show answer
Correct Option: A
Explanation:
  • Vernalisation is defined as the qualitative or quantitative dependence of plants on exposure to a low temperature to flower. Temperature affects flowering, metabolic activities, and germination of seeds in plants. Plants that grow in mild weather germinate at low temperatures whereas those that grow in hot regions germinate at high temperatures. 
  • Some plants need exposure to a low temperature to germinate. Furthermore, a plant can be induced to flower in a growing season by exposing it to low temperature. Therefore, it shortens the vegetative phase and hastens flowering in plants. 

So, the correct answer is A.

Vernalization is subjected to plants growing in 

vernalisation plant growth growth and development plant growth and development biology

  1. Tropical areas

  2. Sub tropical

  3. Temperate areas

  4. Hot areas/Arctic region

Show answer
Correct Option: C
Explanation:
Vernalization refers to the phenomenon of inducing flowering in plants by subjecting them to prolonged cold temperatures. After vernalization, plants acquire the ability to flower. Vernalization is subjected to plants growing in Temperate(temperature in these regions is moderate) areas.
So, the correct answer is 'Temperate areas'.