Tag: plants: structure and function

Quizzes (27) Questions (150)

Questions Related to plants: structure and function

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

Match List I and List II and select the correct option.

   List I    List II
 A  Auxin  1  Herring sperm DNA
 B  Cytokinin  2  Inhibitor of growth
 C  Gibberellin  3  Apical dominance
 D  Ethylene  4  Epinasty
 E  Abscisic acid  5  Induces amylase synthesis

  1. A- 3, B- 1, C- 5, D- 4, E- 2

  2. A- 1, B- 2, C- 3, D- 4, E- 5

  3. A- 5, B- 4, C-2, D- 3, E- 1

  4. A- 2, B- 3, C- 1, D- 4, E- 5
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Auxin plant hormone induces apical dominance. Apical dominance is the growth of the shoot apex of plant. It increases the height of the plant.
Cytokinins were first discovered in 1955 as promoters of cell division in the DNA of Herring sperm. Since, that discovery many different compound with cytokinin activity have been discovered, both natural and synthetic (diphenylurea).
Gibberellin induces the synthesis of $\alpha$-amylase in the aleurone layers. GAs are plant hormones that regulate growth and influence various developmental processes, including stem elongation, germination, dormancy, flowering, sex expression, enzyme induction and leaf and fruit senescence.
Epinasty is the downward bending of a leaf or other plant part, resulting from greater growth of the upper side than of the lower side. Ethylene is the phytohormone which promotes epinastic movement in plants. It also promotes early ripening of fruits.

Abscissic acid promotes seed dormancy, inhibits seed germination, inhibits fruit ripening, induces stomatal closure, etc.
Thus, the correct answer is option A.

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

Which one of the following plant hormones (phytohormone) is known as a stress hormone?

  1. Gibberellins

  2. Kinetin

  3. Auxin

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

The synthesis of ABA is stimulated by drought, water logging and other adverse environmental condition. Therefore, it is also called as stress hormone. It is also called as 'growth inhibitor hormone', because it causes inhibition of seed germination, flowering and so on.

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

Abscisic acid treatment results in ..................

  1. Leaf expansion

  2. Stem elongation

  3. Stomatal closure

  4. Root elongation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
ABA inihibits the H+/K+ exchange and promotes the leakage of maleic acid. The reduction of osmotically active solutes would render the guard cells flaccid and keep the stomatal pore closed. ABA is a growth inhibitor which retards or suppresses growth and metabolism. It induces bud dormancy in a number of plants. In perennial plants, ABA causes the active axillary buds to become dormant
So, the correct answer is 'Stomatal closure'
Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

One hormone helps in ripening of fruits while the other stimulates closure of stomata. These are respectively ..................

  1. Abscisic acid and auxin

  2. Ethylene and abscisic acid

  3. Anscisic acid and rthylene

  4. Ethylene and gibberellic acid

  5. Gibberellic acid and abscisic acid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ethylene hormone in plants helps in ripening of fruits. Abscisic acid is known for its inhibiting nature in growth. It causes bud dormancy in several plants. It also causes closure of stomata to minimize the loss of water by transpiration.

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

In the extreme drought condition, which of the following plant hormone is produced, due to which stomata closes?

  1. ABA

  2. IAA

  3. Gibberellin

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

ABA is a plant hormone which is inhibiting in nature. It causes the closure of stomata, in order to reduce the rate of transpiration and the loss of water thereby. It is also well known for its dormant activity. ABA promotes early aging in the plant and also inhibits flowering, fruiting, germination, etc. 

Thus, the correct answer is option A.

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

Match the items in Column I with Column II and choose the correct option.

   List I   List II 
 A  Human urine  1  Cytokinin
 B  Gibberella fujikuroi  2  Auxin
 C  Herring fish DNA  3  Ethylene
 D  Ripening fruits  4  Abscisic acid
 E  Aged leaves of plants  5  Gibberellins

  1. A- 2, B- 5, C- 1, D- 3, E- 4

  2. A- 1, B- 2, C- 3, D- 4, E- 5

  3. A- 3, B- 5, C- 1, D- 2, E- 4

  4. A- 5, B- 2, C- 1, D- 3, E- 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Human urine - auxin. Human urine commonly shows the presence of Indole acetic acid, compound having similar properties to that of auxin.It was first discovered in 1931 by Kogl and Haagen Smit, five years earlier the discovery of auxins.
Gibberella fujikori - Gibberellin. G.fujikori is a fungal plant pathogen. It causes bakane disease in rice seedlings, by overloading them with the phytohormone; gibberellin as its own metabolic product.
Herring fish DNA - cytokinin. Cytokinins were first discovered in 1955 as promoters of cell division in the DNA of Herring sperm. Since, that discovery many different compound with cytokinin activity have been discovered, both natural and synthetic (diphenyurea).
Ripening fruits - ethylene. Ethylene is the only phytohormone present in gaseous state. It helps in inducing early ripening when sprayed to fruits.
Aged leaves of plants - ABA. Abscissic acid promotes the early aging of leaves, also called as senescence. Aging, dormancy of buds, inducing stomatal closure, inhibiting fruit ripening, etc, are the functions of ABA.

Thus, the correct answer is option A.

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

Senescence as an active developmental cellular process in the growth and functioning of a flowering plant, is indicated in 

  1. Annual plants

  2. Floral parts

  3. Vessels and tracheid differentiation

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

Senescence is a programmed developmental process. Leaf abscission is a classic example of programmed cell death and senescence in plants, allowing the plant to shed older or damaged leaves.

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

An antitranspirant is

  1. Phenyl mercuric acid

  2. Abscisic acid

  3. Salicylic acid

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

Antitranspirants are compounds applied to the leaves of plants to reduce transpiration. Some examples are phenylmercury acetate, abscisic acid (ABA), and aspirin (acetyl salicylic acid). ABA is a well-known antitranspirant.
Thus, the correct answer is an option (D). 

Multiple choice biology chemical coordination in plants abscisic acid fruit plants: structure and function

Which one is not a growth promoter?

  1. ABA

  2. GA

  3. IAA

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

There are various plant hormones which act as growth regulators. Hormones like gibberellic acid (GA), Indoleacetic acid (IAA), a type of auxin, cytokinin (CK) are growth promoter. Hormones like Abscisic Acid (ABA), ethylene are growth inhibitor. These hormones accelerate abscission process.

Thus, the correct answer is option A.