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 life within the seed developmental journey of seed introduction to plant organs and germination seed to plants

Choose the correct answers from the alternatives given.
The following are requirement of seeds for germination to occur:

  1. oxygen for increased metabolism

  2. adequate temperature

  3. adequate water

  4. all of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Seed germination requires oxygen for cellular respiration, an adequate temperature for enzymatic activity, and water for metabolic activation and imbibition.

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

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. 

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 as 

  1. Chelation

  2. Scarification

  3. Vernalization

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

Stratification involves the treatment of seeds at low temperature (5-10 degree C) under sufficiently moist conditions to break its dormancy and to induce germination.

Scarification involves damage or breakage of seed coat by physical methods or chemical methods to break seed dormancy.
Vernalization and Chelation are the methods of cooling of seed during germination in order to accelerate flowering when it is planted. Hence option D is correct.

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

Which of the following is associated with dormancy of seeds?

  1. IBA

  2. GA

  3. Ethylene

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

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. Counteracting Inhibitors: Inhibitors are destroyed by dipping seeds in KNO$ _3$, thiourea, ethylene chlorohydrin and gibberellin. IBA, GA, ethylene are counteracting inhibitors of seed dormancy while ferulic acid is a germination inhibitor. So, the correct answer is 'Ferulic acid'.

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.