Explore how plant growth regulators impact agriculture with these essential questions about plant hormones and their uses. Build a solid understanding of auxins, gibberellins, cytokinins, inhibitors, and their practical roles in farming.
Which plant growth regulator is primarily responsible for promoting root development and cell elongation in plants?
Explanation: Auxin stimulates root growth and cell elongation, making it vital for plant propagation and development. Ethylene mainly influences fruit ripening and leaf abscission. Abscisic acid acts as a growth inhibitor and helps plants withstand stress. Jasmonic acid is involved in plant defense responses rather than primary growth processes.
A farmer applies a hormone to rice plants to induce stem elongation and increase yield; which hormone is most likely used?
Explanation: Gibberellins promote stem elongation and have been used to increase the size and yield of crops like rice. Cytokinin promotes cell division but is less involved in stem elongation. Ethylene speeds fruit ripening and leaf drop. Salicylic acid is primarily linked to plant defense, not stem growth.
Which plant hormone is commonly used to regulate the ripening of fruits during commercial storage and transport?
Explanation: Ethylene is a natural plant hormone that triggers and regulates fruit ripening, making it ideal for managing crops during storage. Gibberellin aids growth but not ripening. Auxin controls cell elongation and root initiation, while cytokinin encourages cell division but does not influence fruit ripening.
When growing plants from tissues in a laboratory, which hormone is typically used to encourage cell division and shoot formation?
Explanation: Cytokinin promotes cell division and is essential for shoot formation in tissue culture techniques. Auxin favors root development. Abscisic acid inhibits growth and is not helpful in tissue culture for regeneration. Brassinosteroids also support plant growth but are not the primary choice for cell division in this context.
Which plant growth regulator helps seeds remain dormant and plays a key role in helping plants tolerate drought?
Explanation: Abscisic acid induces seed dormancy and helps plants manage water stress during drought by closing stomata. Gibberellin generally promotes germination, ethylene is linked to fruit ripening, and auxin does not play a key role in dormancy or drought tolerance.