Tag: plant growth

Quizzes (10) Questions (270)

Questions Related to plant growth

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Read the given statements to identify the phytohormone that performs these functions.


(i) Horizontal growth of seedlings, swelling of the axis and apical hook formation in dicot seedlings.
(ii) Promoting senescence and abscission of leaves and flowers.
(iii) Breaking seed and bud dormancy.
(iv) Initiating germination in peanut seeds.
(v) Sprouting of potato tubers.

  1. ABA

  2. Ethylene

  3. GA

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

Ethylene inhibits longitudinal growth but stimulates transverse or horizontal growth and swelling of axis. It decreases the sensitivity to gravity. Roots become Apo-geotropic while stems turn positively geotropic. Leaves and flowers undergo drooping. The phenomenon is called epinasty. Seedlings develop tight epicotyl hook. It hastens the senescence of leaves and flowers.Abscission of various parts (leaves, flowers, fruits) is stimulated by ethylene which induces the formation of hydrolases. It breaks the dormancy of buds, seeds and storage organs. Rhizomes, corms, tubers, seeds (e.g., Peanut) and other storage organs can be made to sprout early by exposing them to ethylene. Initiates germination in peanut seeds. 

So, the correct answer is 'Ethylene'



Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

The hormone which reduces transpiration rate by inducing stomatal closure is _________________.

  1. ABA

  2. ethylene

  3. cytokinin

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

ABA (Absisic acid) is a stress hormone which is synthesised by the plant during drought or other stress conditions. It causes rapid movement of $K^+$ ions out of the guard cells, closes stomatal pores and thus reduces the transpiration rate.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Hormone responsible for ageing in plants is

  1. GA

  2. IAA

  3. ABA

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

A- GA or Gibberellic acid helps in promoting the growth and the elongation of cells.

B- IAA or Indole acetic acid induces cell elongation and cell division with all subsequent results for plant growth and development.
C- ABA or Abscisic acid is responsible for ageing in plants as well as important for plants in the response to drought, soil salinity etc.
D- Cytokinin, a plant hormone involved in cell growth and differentiation, but also affect apical dominance, axillary bud growth.
So, the correct option is 'ABA'.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

ABA is degraded into 

  1. Mallic acid

  2. Oxalic acid

  3. Phaseic acid

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Abscisic acid is also called stress hormone because the produc­tion of hormone is stimulated by drought, waterlogging, and other adverse environmental conditions. Abscisic acid is known as dormin as it induces dormancy in buds, underground stems, and seeds. ABA is degraded to phaseic acid via CYP707A (a group of P450 enzymes). 
So, the correct answer is 'Phaseic acid'.

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Which one of the following triggers the ripening of fruits?

  1. Ethylene

  2. Indoleacetic acid

  3. Gibberellic acid

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

Ethylene is a simple gaseous plant growth regulator (PGR). It is synthesised in large amounts by tissues undergoing senescence and ripening fruits. the hormone enhances the respiration rate during ripening of the fruits. Ethylene helps fruits ripen by making them softer, through the breakdown components of the cell walls, and sweeter, through the conversion of starches to sugars.

Thus, the correct answer is option A.  

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones
Test Group 1 Test Group 2 Test Group 3
Pair of ripe apples One ripe apple, one unripe apple Pair of unripe apples

Presence of ethylene gas causes fruits to ripen. As fruit ripens, it produces increasing amounts of ethylene. An investigator placed fruit samples sealed containers as shown in the image, and left them for three days. At the end of the time period, the investigator used iodine to test for the presence of starch.

List these in order from highest to lowest starch content.

  1. Group 1, Group 2, Group 3

  2. Group 3, Group 2, Group 1

  3. Group 1, Group 3, Group 2

  4. Group 3, Group 1, Group 2
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The iodine test is used to test Starch content. The solution of iodine contains, an aqueous solution of 1.8% iodine and 3.0% potassium iodide, binds with starch, producing a dark color. The fruits which show more stain the fruit shows, the more starch it contains and the less ripe it is.

So the correct option is 'Group 3, Group 2, Group 1.'

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

One hormone stimulates the closure of stomata and another one influences the swelling of the axis in dicot plants. They are 

  1. Gibberellins and ethylene

  2. Abscisic acid and cytokinins

  3. Gibberellins and cytokinins

  4. Auxins and cytokinins

  5. Abscisic acid and ethylene
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Abscisic acid is a plant hormone. It is also called as a stress hormone. During adverse environmental conditions, it's concentration increases. During water stress condition, it stimulates closure of stomata and hence decreases transpiration rate. Ethylene is also a plant hormone. It shows the triple response. It influences the horizontal growth of seedlings, swelling of the axis and apical hook formation in dicot plants.

Thus, the correct answer is option E. 

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Parthenocarpic fruit cannot be produced by application of

  1. IAA

  2. 2, 4-D

  3. ABA

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

Parthenocarpy is the process of producing seedless fruits without fertilization. Various phytohormones are used to produce parthenocarpic fruit. Auxin hormone like IAA, IBA, 2, 4 -D are most widely used to induce parthenocarpy. It can also be induced by application of gibberellin hormone.

Thus, the correct answer is option C.