Biology · Environmental Studies

Plant Reproduction and Germination

892 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

Prechilling treatment to break seed dormancy is

  1. Scarification

  2. Vernalisation

  3. Impaction

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

A. Scarification: Hard, impermeable seed coat is weakened or ruptured by filing, chip­ping, hot water 

B. Vernalisation- The cooling of seed during germination in order to accelerate flowering when it is planted.

C Impaction- It means to strike something with force. This method implies to the vigorous shaking of the seeds

D. Stratification: Seeds are moistened and exposed to oxygen for variable period at very low (chilling) or high temperature.

So, the correct answer is 'Stratification'.

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

Thiourea is used in overcoming seed dormancy by

  1. Chemical scarification

  2. Counteracting inhibitors

  3. Inducing cell division

  4. Develop osmotic pressure
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Thiourea acts as a chemical agent that helps break seed dormancy by counteracting the effects of germination inhibitors present in the seed.

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

Seeds of some plants do not germinate even under favourable conditions due to

  1. Dormancy

  2. Quiescence

  3. Vivipary

  4. Non-viability
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Quiescence is a condition in which seeds do not germinate due to unfavourable environmental conditions. When favrouable conditions return, the seed will germinate. Seeds of some plants do not germinate even under favourable conditions. This is called as dormancy. It is under endogenous control.

Thus, the correct answer is 'Dormancy'.

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

Seed dormancy may be due to

  1. Permeable seed coat

  2. Hard impermeable seed coat

  3. Thin seed coat

  4. Lack of reserve food
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Reasons of seed dormancy:

1. Immaturity of embryo: Embryo is immature at the time of seed shedding. The seed will remain dormant till the embryo becomes mature, e.g., Anemone nemorosa, Ranunculus ficaria.

2. After-Ripening: The seeds require a period of dry storage for developing the ability to germinate, e.g., Wheat, Oat, Barley.

3. Impermeable seed coat: The seed coat is impermeable to water and gases, e.g., Apple, Chenopodium.

4. Hard seed coat: The seed coat is mechanically resistant and does not allow the embryo to grow, e.g., Amaranthus, Lepidium.

5. Germination Inhibitors: They occur in the seed coats and cotyledons of the embryos. The important germination inhibitors causing seed dormancy are abscisic acid, phenolic acid, ferulic acid, coumarin, short fatty acids and cyanogenic chemicals, e.g., Apple, Peach, Ash, Cucurbita, Iris, Xanthium.

So, the correct answer is ‘Hard impermeable seed coat’.

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

Seed dormancy allows the plants to

  1. Overcome unfavourable climatic conditions

  2. Develop healthy seeds

  3. Reduce viability

  4. Prevent deterioration of seeds
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Seed dormancy is an adaptive mechanism that prevents germination during unfavorable environmental conditions, ensuring the plant germinates only when conditions are suitable for survival.

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

Dormancy is absent in seeds of ______________.

  1. Wheat

  2. Maize

  3. Rhizophora

  4. Cycas
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Rhizophora exhibits vivipary, a phenomenon where seeds germinate while still attached to the parent plant, meaning seed dormancy is absent. Wheat, maize, and Cycas seeds normally undergo a period of dormancy before germination. Viviparous mangrove plants lack this resting stage to survive tidal environments.