Q. No.In order to increase the yield of sugarcane crops, which of the following plant growth regulators should be sprayed?
1.
Ethylene
2.
Auxins
3.
Gibberellins
4.
Cytokinins
Removal of shoot tips is a very useful technique to boost the production of tea leaves. This is because:
| 1. | Gibberellins prevent bolting and are inactivated. |
| 2. | Auxins prevent leaf drop at early stages. |
| 3. | Effect of auxins is removed and the growth of lateral buds is enhanced. |
| 4. | Gibberellins delay the senescence of leaves. |
Select the correct match
| 1. | Auxin | – Promote seed dormancy |
| 2. | Cytokinin | – Overcoming apical dominance |
| 3. | Ethylene | – Bolting in beet |
| 4. | GA3 | – Thinning of cherry and walnut |
In a flowering plant if auxins are not synthesizing, then effects which would most probably be seen in this plant are
| i | Dropping of fruits at early stage. |
| ii | Inhibition in the growth of lateral buds. |
| iii | Delayed abscission of older mature leaves. |
| iv | Inhibition of cell division in cambium. |
| 1. | i, ii and iv |
| 2. | i, iii and iv |
| 3. | ii and iv only |
| 4. | i and iii only |
The phytohormone which promotes rapid internode elongation in deep water rice plant is
| 1. | Gibberellins | 2. | Ethylene |
| 3. | Auxin | 4. | Cytokinin |
Ethephon hastens the fruit ripening in tomatoes and apple and accelerates abscission in flowers and fruits. Above statement indicates that ethephon must release –
1. ABA
2. C2H4
3. IAA
4. GA7
| A. | _______ hormone is most widely used PGR in agriculture. |
| B. | _______ hormone is related with Richmond Lang effect. |
| A | B | |
| 1. | Auxin | CK |
| 2. | Auxin | GA |
| 3. | Ethylene | CK |
| 4. | ABA | CK |
Kinetin (cytokinin) was first discovered as a breakdown products of
1. DNA
2. t-RNA
3. Spindle fibres
4. m-RNA
Thinning of cotton and promotion of femaleness in cucumber are physiological effects of PGR which
| 1. | Helps of withstand desiccation conditions and is antagonistic to GAs |
| 2. | Increases the market period of fruits by delaying senescence |
| 3. | Is synthesized in large amounts in ripening fruits and tissues undergoing senescence |
| 4. | Prevents fruit and leaf drop at early stages and produced by growing apices of stem |
Plant growth regulator, which promotes senescence and abscission of plant organs, is also related to which of the following physiological effects?
| 1. | Thinning of cotton, cherry, and walnut |
| 2. | Overcome apical dominance |
| 3. | Early seed production in conifers |
| 4. | Formation of new leaves |
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