Plant Hormones

Q: What are auxin and gibberellin?

A: Auxin and gibberellin are plant hormones that regulate growth and development. Auxin is primarily responsible for cell elongation, root initiation, and tropisms, while gibberellin promotes seed germination, stem elongation, and flowering

Q: Where are auxins produced in plants?

A: Auxins are mainly produced in the apical meristem of shoots, young leaves, and developing seeds

Q: What are auxin and gibberellin?

A: Auxin and gibberellin are plant hormones that regulate growth and development. Auxin is primarily responsible for cell elongation, root initiation, and tropisms, while gibberellin promotes seed germination, stem elongation, and flowering

Q: Where are auxins produced in plants?

A: Auxins are mainly produced in the apical meristem of shoots, young leaves, and developing seeds

Q: Where are gibberellins produced in plants?

A: Gibberellins are produced in young leaves, roots, and seeds, particularly during germination.

Q: How does auxin contribute to phototropism?

A: Auxin redistributes to the shaded side of a plant, causing cells on that side to elongate more, which bends the plant toward the light.

Q: How does gibberellin promote seed germination?

A: Gibberellin stimulates the breakdown of food reserves in seeds by activating enzymes like amylase, which converts starch into sugars for energy during germination

Q: How do auxin and gibberellin contribute to stem elongation?

A: Both auxin and gibberellin promote stem elongation by stimulating cell division and elongation. Gibberellin is particularly important for rapid elongation in certain plants

Q: What is apical dominance, and what role does auxin play?

A: Apical dominance is the suppression of lateral bud growth by the apical bud. Auxin produced in the apical bud inhibits the growth of lateral buds, maintaining the plant's vertical growth

Q: How do auxin and gibberellin interact in plant growth?

A: Auxin and gibberellin often work together to regulate growth processes, such as stem elongation and organ formation. Their interaction ensures coordinated development

Q: How does gibberellin influence flowering?

A: Gibberellin promotes flowering in some plants by stimulating the development of floral organs and inducing flowering in response to environmental cues.

Q: What role does auxin play in root growth?

A: Auxin regulates root growth by promoting the formation of lateral and adventitious roots. It also influences root elongation depending on its concentration

Q: What happens if auxin levels are too high in a plant?

A: Excessive auxin can inhibit growth by disrupting normal cell elongation and division, particularly in roots.

Q: What role does gibberellin play in fruit development?

A: Gibberellin promotes fruit growth and can induce parthenocarpy (development of seedless fruits) in some plants.

Q: What are the primary functional differences between auxin and gibberellin?

A: Auxin primarily regulates cell elongation, root initiation, and tropisms, while gibberellin is more involved in seed germination, stem elongation, and flowering

Q: How does auxin regulate tropisms in plants?

A: Auxin redistributes in response to environmental stimuli, such as light (phototropism) or gravity (gravitropism), causing differential growth and bending of the plant

Q: How are auxin and gibberellin used in agriculture?

A: Auxin is used to promote rooting in cuttings and prevent premature fruit drop, while gibberellin is used to increase fruit size, induce seedless fruit production, and promote uniform germination.