Tag: growth and development

Quizzes (7) Questions (180)

Questions Related to growth and development

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. Gibberellin

  3. Indoleacetaldehyde

  4. Indole-3-butyric acid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Apical dominance is a physiological response of auxins. The chemicals mentioned in options A, C and D are all auxins. They inhibit the growth of axillary buds and stimulate the growth of apical bud. This phenomenon is called as apical dominance. Gibberellins are also growth promoting phytohormones. They stimulate internodal elongation. Thus, bringing about an increase in length or height of plants.

Thus, the correct answer is option B.

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

Who demonstrated that cut tip of canary grass seedlings resume phototropic sensitiveness when pasted back in its position?

  1. Charles Darwin

  2. F W Went

  3. Boysen Jensen

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

Charles Darwin used cut tip of canary grass seedlings to demonstrate the sensitivities of the stem apex to light mediated movements. 

Boysen used Avena cut tips to demonstrate presence of plant hormones. 
Paal showed through his experiments that some other growth promoting substances are present in cut tips. 
Hence, option A is correct. 

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.