BOTANY
AGRONOMY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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the twisting and bending of plant leaves and stems due to an auxin
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the discoloration of leaves caused by a toxin
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interveinal yellowing of leaves caused by a nutrient deficiency
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spotting of leaves from a contact herbicide
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Detailed explanation-1: -Leaf epinasty involves the downward bending of leaves as a result of disturbances in their growth, with a greater expansion in adaxial cells as compared to abaxial surface cells. The co-ordinated anisotropy of growth in epidermal, palisade mesophyll and vascular tissues contributes to epinasty.
Detailed explanation-2: -When light is coming from one side of the plant, auxin diffuses towards the shady side of the shoot. This concentration of auxin stimulates the cells to grow longer on the side of the shoot which is away from light. Thus, the plant appears to bend towards light.
Detailed explanation-3: -Auxin is a key regulator of plant growth and development, orchestrating cell division, elongation and differentiation, embryonic development, root and stem tropisms, apical dominance, and transition to flowering.
Detailed explanation-4: -Epinasty is the downward bending of a leaf resulting from greater growth of the upper side than of the lower side. Due to more growth on the upper side, the flower will open due to epinasty. The hyponasty is an upward bending of leaves resulting from greater growth of the lower side.