Tag: biology

Quizzes (1160) Questions (12174)

Questions Related to biology

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

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

  1. Seed dormancy

  2. Arctic tern

  3. Diapause

  4. Hibernation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Escape in time refers to strategies like dormancy, diapause, or hibernation that allow organisms to survive unfavorable periods. The Arctic tern is a migratory bird, which is an example of escape in space.

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.

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

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

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 biology cell division cell division in embryo development division for growth and reproduction structure of chromosome, cell cycle and cell division mitosis

Which stage of cell cycle occurs immediately prior to mitosis 

  1. $M$
  2. $G _1$
  3. $S$
  4. $G _2$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$G _2$ phase is the phase of cell cycle occurs immediately prior to mitosis.
sequence of cell cycle is -- $G _1$ to $S$ to $G _2$ to $M$ to cytokinesis.

So, the correct answer is '$G _2$

Multiple choice biology mineral nutrition in plants hydroponics nutrients and nutrition hydroculture

Which one of the following roles is not charcteristic of an essential element?

  1. Being a component of biomolecules

  2. Changing the chemistry of soil

  3. Being a structural component of energy related chemical compounds.

  4. Activation or inhibition of enzymes.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A dirt's fruitfulness, which is a substantial property, is simpler to change than the dirt's physical properties. A natural issue, the dirt minerals present, and the seepage conditions all impact soil shading. 

So, the correct option is 'Changing the chemistry of soil'.

Multiple choice biology mineral nutrition in plants hydroponics nutrients and nutrition hydroculture

Which of the following is not a deficiency symptom of minerals?

  1. Internode shortening

  2. Necrosis

  3. Chlorosis

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

Etiolation is a process in plants grown in partial or complete absence of light, characterized by long, weak stems and pale yellow leaves. It is a developmental response to light deprivation, not a symptom of mineral deficiency.