HORT 2050- Exam 3 LSU Questions And Answers

HORT 2050- Exam 3 LSU Questions And Answers Flower induction - ANS start of flowering process in response to certain stimuli (the shoot apical meristem becomes competent to develop flowers) Flower initiation - ANS change in the meristematic tissue from vegetative to reproductive What triggers induction and initiation in flower buds? - ANS -Photoperiod/phytochrome (length of exposure to light/ plant's reaction to it) -Vernalization (any temperature treatment that promotes flowering) Vernalization - ANS the cooling of seed during germination in order to accelerate flowering when it is planted What are chilling hours? - ANS Hours of sustained cold, between 32 - 45 degrees F What type of plants does vernalization work with? - ANS -spring blooming perennials -biennials -bulbs Pollination - ANS transfer of pollen from anther to stigma What are the primary modes of transfer for pollen? - ANS wind and insects Fertilization - ANS combination of male and female gametes that create an embryo Fruit senescence - ANS deterioration of fruit that leads to ripening Steps of Reproductive Growth - ANS 1. Differentiation and Development (growth and development of floral structures) 2. Pollination 3. Fertilization 4. Fruit set and seed formation 5. Growth and maturation of fruit and seed 6. Fruit senescence Define hormones - ANS -naturally produced compounds that influence growth -"chemical messengers" Plant Growth Regulators (PGR) - ANS Synthesized compounds that can regulate plant growth similar to naturally produced hormones What are the five basic groups of plant hormones? - ANS -Cytokinins -Auxins -Abscisic Acid -Gibberellins -Ethylene (think CAGE) Which plant hormones are growth promoters? - ANS -Cytokinins -Auxins -Gibberellins Which plant hormones influence gas, ripening, and senescence? - ANS Ethylene Which plant hormones are growth inhibitors? - ANS Abscisic acid Describe auxin. - ANS -primary hormone that encourages growth -produced in shoot tips and translocated downward -maintains apical dominance Apical Dominance - ANS -dominant growth of the central stem -phenomenon in which the closer a bud is to the stem's tip, the more its growth is inhibited -hormone controlled -species dependent -defines the form of the plant (like an evergreen) What is an example of a natural auxin? Synthetic? - ANS -natural: IAA -synthetic: IBA, NAA Commercial uses of auxin - ANS -rooting compounds -Weed Control 2,4-D -fruit thinning Describe gibberellins (GA) - ANS -stimulates cell elongation -overcomes seed and bud dormancy -produced in shoot tips and roots -travels in both directions in plant Commercial uses of gibberellins - ANS -increase fruit size -seed germination -promote flowering What does PGR stand for? - ANS Plant Growth Regulators Describe cytokinins. - ANS -promote cell division and tissue differentiation -found in all tissue with active cell division