Tag: plant growth and development

Quizzes (13) Questions (188)

Questions Related to plant growth and development

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

Name the plant hormone associated with apical dominance.

  1. Auxin

  2. Ethylene

  3. Cytokinin

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Apical dominance is a phenomenon wherby, the inhibition of the growth of lateral buds occurs due to the terminal bud of a shoot.
  • It is caused by the production of IAA (auxin) in abundance by the apical bud.
  • This auxin is transported basipetally from the apical bud.
  • The auxin causes the lateral buds to remain dormant. 
Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

Avena coleoptile test to find out the amount of growth promoting hormones was discovered by

  1. F W. Went

  2. LJ.Odum

  3. K.V Thimann

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

F. W. Went in 1928 used tip of Avena coleoptile. He removed the tip of Avena coleoptile and and placed in on the agar agar block for the definite measured amount of time. Then this agar agar block was placed asymmetrically on the stump, this showed a positive curvature. 

When this agar agar block was placed centrally on the stump then the growth of the coleoptile was found to be renewed. He named this growth promoting substance or hormone as auxin. 
He also noticed that curvature in Avena coleoptile is proportional, to the amount of auxin in agar agar block. Hence, option A is correct. 

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

The discovery, that during light induced bending of stem the apex produces a diffusible chemical, was made by

  1. Charles Darwin and Francis Darwin

  2. Boysen-Jensen and Paal

  3. Went

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

A tropism is a growth movement by plant part in the direction of the stimulus. According to Boysen-Jensen, the stimulus for phototropism, growth in response to light, is a diffusible chemical that passes from the tip of the coleoptile. He cut the tip of the coleoptile and the severed tip was reattached through a gelatin disc. The recapitated coleoptile showed bending of stem towards light. Paal continued with Boyse-Jensen work. He said that the tip of coleoptile produces some chemical which travels down and stimulates growth. The light causes the accumulation of that chemical on the shaded side of the coleoptile. 

Thus, the correct answer is option B. 

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

Decapitation i.e. removal of shoot tips in a plant usually results in

  1. inactivation of lateral buds

  2. growth of lateral buds

  3. cessation of plant growth

  4. yellowing of leaves.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Apical dominance is the phenomenon by which presence of apical bud does not allow the nearby lateral buds to grow. When the apical bud is removed, the lateral buds sprout. Apical bud inhibits the growth of lateral buds by releasing auxins. When a plant is decapitated i.e., its apical bud is removed then the lateral buds sprout, resulting in dense bushy growth. This phenomenon is widely used in the tea plucking and hedge making.
So the correct answer is 'growth of lateral buds'.
Multiple choice apical dominance auxins and gibberellins growth and development plant growth and development biology

Growth hormone responsible for apical dominance is

  1. Auxin

  2. Cytokinin

  3. Gibberellin

  4. Ethylene
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 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 A.

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

Substances which originate at the tip of stem and control growth elsewhere are

  1. Enzymes

  2. Hormones

  3. Vitamins

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A chemical substance produced in one part of body and regulates the activity of other parts is called as hormones. Plant hormones are produced in the stem, bud and root tips and control the plant growth, formation of flowers, stems, leaves, development, and ripening of fruit, etc. Auxins are specialized hormones which acts on the tip.

Thus, the correct answer is option B.

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

Apical dominance means

  1. Suppression of growth of apical bud by axillary buds

  2. Suppression of growth of axillary buds by the presence of apical buds

  3. Stimulation of growth of axillary buds by removal of apical buds

  4. Inhibition of growth of axillary buds by removal of apical buds
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Auxins are generally produced by the growing apices of the stems and roots, from where they migrate to the regions of their action. In most higher plants, the growing apical bud inhibits the growth of the lateral (axillary) buds, a phenomenon called as apical dominance. 

Apical dominance is thought to be due to production of auxins in the stem tips. Removal of shoot tips (decapitation) usually results in the growth of lateral buds. It is widely applied in tea plantations, hedge-making.

Multiple choice vernalisation plant growth growth and development plant growth and development biology

Vernalization can remove Kernel wrinkles in:

  1. Wheat

  2. Petkus rye

  3. Maize

  4. Rice
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Vernalisation is defined as the qualitative or quantitative dependence of plants on exposure to a low temperature to flower. Temperature affects flowering, metabolic activities, and germination of seeds in plants. Plants that grow in mild weather germinate at low temperatures whereas those that grow in hot regions germinate at high temperatures. 
  • Some plants need exposure to a low temperature to germinate. Furthermore, a plant can be induced to flower in a growing season by exposing it to low temperature. Therefore, it shortens the vegetative phase and hastens flowering in plants. 

So, the correct answer is A.
Multiple choice vernalisation plant growth growth and development plant growth and development biology

Vernalization is subjected to plants growing in 

  1. Tropical areas

  2. Sub tropical

  3. Temperate areas

  4. Hot areas/Arctic region
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Vernalization refers to the phenomenon of inducing flowering in plants by subjecting them to prolonged cold temperatures. After vernalization, plants acquire the ability to flower. Vernalization is subjected to plants growing in Temperate(temperature in these regions is moderate) areas.
So, the correct answer is 'Temperate areas'.
Multiple choice vernalisation plant growth growth and development plant growth and development biology

Which of the following is not true regarding vernalisation

  1. Its a temperature dependent phenomenon

  2. Its a light dependent phenomenon

  3. It prevents precocious reproductive development

  4. Its an aerobic process
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The process of induction of flowering in plants, by exposing seeds at low temperature for prolonged periods is called Vernalisation. It is an aerobic, temperature dependent phenomena, prevents precocious reproductive development. It does not depend on light.

So, the correct answer to the question is ‘vernalisation is not a light dependent phenomena’.