Science
Plant hormones
पादप हार्मोन
In this Class 10 Science topic from the chapter Control and Coordination, students learn how plants coordinate growth and respond to their surroundings without a nervous system. The topic introduces plant hormones such as auxin, gibberellin, cytokinin, abscisic acid and ethylene, explaining their roles in cell growth, seed germination, flowering, dormancy, fruit ripening and leaf fall. Students also connect these chemical signals with responses such as phototropism and geotropism, building a clear understanding of plant regulation and movement.
Practice questions
During drought, slow growth and wilting of leaves in a plant are more related to which hormone?MediumLevel 17What is the most likely effect of applying gibberellin to a dwarf plant?MediumLevel 17If unequal distribution of auxin does not occur in a plant, what will happen to phototropism?MediumLevel 17Which option correctly matches a plant hormone with its function?MediumLevel 17If a chemical increases cell division in a plant but does not directly increase stem length which hormone is it acting like?HardLevel 17Why do target organs respond only to specific hormones?HardLevel 18If a plant receives light from one side and auxin collects on the shaded side, what will happen?MediumLevel 18Why is a tendril able to coil around a support?MediumLevel 18Which statement correctly differentiates the functions of gibberellin and cytokinin?MediumLevel 18How can abscisic acid be useful to a plant during drought?MediumLevel 18Why is it incomplete to describe phototropism only as bending of a plant?HardLevel 16How is downward growth of root and upward growth of stem a survival strategy of a plant?MediumLevel 16Why is it correct to link abscisic acid with protection of a plant during drought?MediumLevel 16What advanced conclusion about plant growth follows from the roles of gibberellin and cytokinin?MediumLevel 16Why would it be wrong to interchange the roles of sensory nerve and motor nerve in a reflex arc?MediumLevel 16Why can the same plant hormone show different effects in a root and a stem?HardLevel 16A plant stem bends towards light in unilateral light. If unequal distribution of auxin is stopped, what will happen?HardLevel 17Why does a plant bend towards light if auxin collects more on the shaded side of the stem?MediumLevel 17High auxin concentration may inhibit growth in roots but promote growth in stems. What conclusion follows from this?HardLevel 17If the effect of cytokinin decreases in a plant, which level of growth may be affected first?MediumLevel 17