Biology · Environmental Studies

Plant Reproduction and Germination

835 Questions

Plant reproduction and germination involve seed structure, cotyledon function, and dispersal mechanisms. These core botany concepts frequently appear in general science sections. Practice these questions to ensure better retention.

Seed germination typesSeed dispersal mechanismsCotyledons and albuminous seedsCryptogamic plantsPhanerogams reproduction

Plant Reproduction and Germination Questions

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

Which one of the following does NOT exhibit seed dormancy?

  1. Rhizophoi

  2. Xanthium

  3. Phaseolus

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

Rhizophora is a mangrove plant that exhibits vivipary, where seeds germinate while still attached to the parent plant, thus lacking seed dormancy.

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

Treatment of seed at low temperature under moist conditions to break its dormancy is called -

  1. Sclarification

  2. Vernalization

  3. Chelation

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

  • Stratification involves the treatment of seed at low temperature(5−10 C)
under sufficiently moist conditions to break its dormancy and to induce germination. 
  • Scarification involves any damage or breakage of seed coat by physical methods (eg, use of a scalpel, wooden hammer, etc) or chemical methods (use of mild acids) to break seed dormancy. 
  • Vernalization and Chelation is the chill treatment Df plant in its early stages of life history to stimulate or induce early flowering

So, the correct answer is 'Stratification'.

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

Which method makes the seed coat permeable and allows growth of embryo?

  1. Scarification

  2. Stratification

  3. Vernalisation

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

Scarification in the method of weakening and opening the seed coat to initiate germination. It makes seed coat permeable. This method is employed for plant species which are impervious to water and gases.

Thus, the correct answer is 'Scarification'.

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

Verbalization is used to overcome chemical dormancy in seeds. The temperature range used for this purpose is?

  1. Zero to $4$ degrees C
  2. $15$ to $20$ degrees C
  3. $20$ to $30$ degrees C
  4. $30$ to $40$ degrees C
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Vernalization (often misspelled as verbalization) is the induction of a plant's flowering process by exposure to the prolonged cold of winter, typically in the range of 0 to 4 degrees Celsius.

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

Consider the following statements regarding allelopathy.
a. It is the phenomenon of seed dormancy due to the presence germination inhibitors on the surface of seed coat.
b. It is the phenomenon of the production of organic substances by one plant having handful effect on the other.
c. It helps proper spacing of the plants to reduce competition.
d. It helps the xerophytes to grow in small groups to reduce the transpiration.
Of these statements.

  1. $1, 2$ and $3$ are correct
  2. $1$ and $3$ are correct
  3. $2$ and $3$ are correct
  4. $1$ and $4$ are correct
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Allelopathy involves the production of chemicals by plants that influence the growth of other plants. Statements 1, 2, and 3 correctly describe aspects of this phenomenon, including germination inhibition and spacing.

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

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
Reveal answer Fill a bubble to check yourself
D Correct answer
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'.

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

Which one does not exhibit seed dormancy?

  1. <p>Phaseolus</p>

  2. <p>Rhizophora</p>

  3. <p>Cassia</p>

  4. <p>Xanthium</p>
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.

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

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

  1. Scarification

  2. Stratification

  3. Vernalization

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
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'

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

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
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.

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

Seed dormancy is associated with

  1. Hard seed coat

  2. Immature embryo

  3. Presence of germination inhibitors

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
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'.
Multiple choice biology plant growth seed dormancy fruit plants: structure and function

Seed dormancy can be broken by the following combination of chemicals

  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 ${GA} _{3}$
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice botany diversity in living things and their classification plant life cycle alternation of generations life span

In the first year of a biennial plant, .......... grows then it enters a period of dormancy over the cold months

  1. Leaves

  2. Stem

  3. Roots

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

In the first year of a biennial plant, the plant typically develops its vegetative structures, including leaves, stems, and roots, to store energy. These structures allow the plant to survive the winter dormancy period before flowering in the second year.

Multiple choice botany diversity in living things and their classification plant life cycle alternation of generations life span

In first year, biennial plants are only

  1. Reproductive

  2. Vegetative

  3. Both A and B

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Biennial are plants whose entire life cycle occurs within two years. In the first year, these plants are only vegetative, meaning that they don't produce reproductive structures. Rather, these plants will grow roots below ground and a small rosette of leaves near the surface