Auxin is used by gardeners to prepare weed-free lawns. But no damage is caused to grass as auxin [2024]
promotes apical dominance
promotes abscission of mature leaves only
does not affect mature monocotyledonous plants
can help in cell division in grasses, to produce growth.
(3)
Auxins are widely used as herbicides by the gardeners to prepare weed-free lawns. 2, 4-D, a synthetic auxin is widely used to kill dicotyledonous weeds but it does not affect mature monocotyledonous plants.
Spraying sugarcane crop with which of the following plant growth regulators increases the length of stem, thus, increasing the yield? [2024]
Auxin
Gibberellin
Cytokinin
Abscisic acid
(2)
Spraying sugarcane crop with gibberellins increases the length of the stem and therefore increases the yield by as much as 20 tonnes per acre.
The phenomenon which is influenced by auxin and also played a major role in its discovery. [2023]
Phototropism
Root initiation
Gravitropism
Apical Dominance
(1)
Phototropism is the movement of shoot towards the light. Auxins get accumulated towards the shady region of the stem which stimulate the cells on that side to grow longer. This results in the bending of stem towards the light. This was seen in the experiments conducted by F.W. Went on Avena coleoptile tips.
Match List-I with List-II. [2023]
| List I | List II | ||
| (A) | Auxin | (I) | Promotes female flower formation in cucumber |
| (B) | Gibberellin | (II) | Overcoming apical dominance |
| (C) | Cytokinin | (III) | Increase in the length of grape stalks |
| (D) | Ethylene | (IV) | Promotes flowering in pineapple |
Choose the correct answer from the options given below:
(A)-(II), (B)-(I), (C)-(IV), (D)-(III)
(A)-(IV), (B)-(III), (C)-(II), (D)-(I)
(A)-(I), (B)-(III), (C)-(IV), (D)-(II)
(A)-(III), (B)-(II), (C)-(I), (D)-(IV)
Which hormone promotes internode/petiole elongation in deep water rice? [2023]
Ethylene
2, 4-D
Kinetin
(1)
Ethylene promotes rapid internode/petiole elongation in deep water rice plants. It helps leaves/upper parts of the shoot to remain above water.
Spraying of which of the following phytohormone on juvenile conifers helps in hastening the maturity period, that leads to early seed production? [2023]
Zeatin
Abscisic Acid
Indole-3-butyric Acid
Gibberellic Acid
(4)
Gibberellins are one of the promotory plant growth regulators. Spraying juvenile conifers with gibberellic acids hastens the maturity period, thus leading to early seed production.
The gaseous plant growth regulator is used in plants to [2022]
speed up the malting process
promote root growth and root hair formation to increase the absorption surface
help overcome apical dominance
kill dicotyledonous weeds in the fields.
(2)
Ethylene is a gaseous plant growth regulator that promotes root growth and root hair formation, thus helping the plants to increase the absorption surface. Gibberellic acid () is used to speed up the malting process in the brewing industry. Cytokinin helps to overcome apical dominance. Auxin kills dicotyledonous weeds in the field.
Production of cucumber has increased manifold in recent years. Application of which of the following phytohormones has resulted in this increased yield as the hormone is known to produce female flowers in the plants [2022]
ABA
gibberellin
ethylene
cytokinin
(3)
Ethylene is a gaseous hormone that promotes female flowers in cucumbers thereby increasing the yield.
The plant hormone used to destroy weeds in a field is [2021]
IBA
IAA
NAA
2, 4-D
(4)
Auxins like 2,4-D act as weedicides by being selectively harmful to broad-leaved dicot weeds.
Name the plant growth regulator which upon spraying on sugarcane crop, increases the length of stem, thus increasing the yield of sugarcane crop. [2020]
Cytokinin
Gibberellin
Ethylene
Abscisic acid
