Tag: apical dominance

Quizzes (0) Questions (42)

Questions Related to apical dominance

Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

I. Assertion: The presence of apical bud inhibits the growth of lateral bud, this is called apical dominance.
II. Reason: Auxin is responsible for apical dominance.

  1. I and II both are wrong

  2. I is wrong and II is correct

  3. I and II both are correct , II is correct explanation for I

  4. I and II both are correct , II is not a correct explanation for I
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Auxins when applied to plant cuttings help in formation of adventitious roots. Higher concentration of auxin at apical bud suppresses growth of lateral bud having low concentration of auxin.

Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

Apical dominance is not affected by ...................

  1. Indole acetic acid

  2. Gibberellic acid

  3. Indole acetaldehyde

  4. Indole butyric acid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

GA promotes the elongation of plants by inducing the division of lateral meristem. Whereas, the phytohormone auxin causes the apical dominance in plants. In the given options all other options other than gibberellic acid accounts for different types of auxin.

Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

A potted plant placed near the window bends outwardly due to 

  1. Greater oxygen availability to the tip.

  2. More auxin content on the shaded side.

  3. Greater light availability to tip.

  4. Availability of necessary warmth to the tip.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Greater growth on the shaded side of the stem is due to more accumulation of auxin on the shaded  side than on the illuminates. Auxin causes bending of plant towards light. Phototropism is induced by auxin hormone.

Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

Removal of apical bud makes the plant

  1. Bushy

  2. Grow rapidly

  3. Grow slowly

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

Apical dominance is a phenomenon in which main stem grows faster than the lateral branches. Apical bud produces auxin hormone that promotes apical dominance and inhibits growth of the lateral buds. When the apical bud is removed, the source of auxin is removed. Due to this, the lateral buds grow faster and makes plant bushy. 

Thus, the correct answer is option A.

Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

Apical dominance is caused by

  1. Abscisic acid in lateral bud

  2. Cytokinin in leaf tip

  3. Gibberellin in lateral buds

  4. Auxin in shoot tip
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Apical dominance is a phenomenon in which central stem is dominant and lateral stems are suppressed. It is due to plant hormones produced in the tip of the shoot. Auxin hormone is responsible for apical dominance and cytokinin hormone is responsible for breaking the apical dominance. 

Thus, the correct answer is option D.

Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

The hormones responsible for apical dominance is

  1. IAA

  2. GA

  3. ABA

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

Apical dominance is a phenomenon in which central stem is dominant and lateral branches are suppressed. It is due to plant hormones produced in the tip of the shoot. IAA, a type of auxin hormone is responsible for apical dominance and cytokinin hormone is responsible for breaking the apical dominance. 

So, the correct answer is 'IAA'

Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

Apical dominance as found in higher plants is due to

  1. Photoperiodism

  2. Phototropism

  3. Hormones

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

Apical dominance is a phenomenon in which central stem is dominant and lateral stems are suppressed. It is due to plant hormones produced in the tip of the shoot. Auxin hormone is responsible for apical dominance and cytokinin hormone is responsible for breaking the apical dominance. 

Thus, the correct answer is option C.

Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

Removal of apical bud results in

  1. Formation of new apical bud

  2. Elongation of main stem

  3. Death of plant

  4. Formation of lateral branching
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Apical dominance is a phenomenon in which central stem is dominant and lateral stems are suppressed. It is due to plant hormones produced in the tip of the shoot. Auxin hormone is responsible for apical dominance. When apical bud is removed, there is growth of lateral bud. This results in formation of lateral branching. This makes plant bushy.

Thus, the correct answer is option D.

Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

Lateral axillary buds are not allowed to grow by

  1. Auxin

  2. Ethylene

  3. Gibberellin

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

Apical dominance is a phenomenon in which central stem is dominant and lateral stems are suppressed. It is due to plant hormones auxin produced in the tip of the shoot. It promotes apical dominance and does not allow lateral axillar buds to grow. However, when tip of the shoot is cut, it promotes the growth of lateral axillary buds.

So, the correct answer is 'Auxin'

Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

Auxins promote

  1. Apical dominance

  2. Cambial activity

  3. Cell growth

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

Apical dominance is a phenomenon in which central stem is dominant and lateral stems are suppressed. It is due to plant hormone auxin produced in the tip of the shoot. Auxin hormone is responsible for apical dominance and cytokinin hormone is responsible for breaking the apical dominance. 

Thus, the correct answer is 'Apical dominance'.