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level: Level 1 of wk2bCultivation of plants

Questions and Answers List

level questions: Level 1 of wk2bCultivation of plants

Question	Answer
Amount of active constituents responsible for therapeutic activities of crude drugs is affected by the __	cultivation process
Advantage of cultivation	1 Ensures quality and purity of medicinal plants 2 Gives better yield and therapeutic quality 3 Ensures regular supply of a crude drug 4 Cultivation leads to industrialization of greater extent. 5 application of modern technology such as mutation, polyploidy and hybridization.
Properties of soil that play crucial role in growth of plants	Physical – water holding capacity affects plant Chemical – calcium present in soil may be beneficial to other plants but not to all Microbiological - microorg present in soil affect plants ex. actinomycetes
Methods of propagation	1 Sexual method (seed propagation) 2 Asexual method
a natural substances (produced by plant) that acts to control plant activities.	Plant hormones
5 recognized groups of natural plant hormones and growth regulators.	1 Auxins 2. Gibberellins 3. Cytokinins 4. Ethylene 5 Abscissic acid
include plant hormones (natural & synthetic) but also include non-nutrient chemicals not found naturally in plants that when applied to plants, influence their growth and development.	Plant growth regulators
Influence plant growth – found in leaves and stems Cell enlargement or elongation – located in meristems and shoot tips (terminal & lateral buds). move mainly from apex (top) down. Lengthening of the internodes and influence the developing embryos in the seed. Hormone-indoleacetic acid (IAA)- naturally occurring	Auxins
What happens when auxin is added to a stem?	The stem will bend away from the auxin. It elongates faster on the extra auxin side.
Have a regulatory function Are produced in the shoot apex primarily in the leaf primordial (leaf bud) and root system Stimulates cell division, cell elongation (or both) and controls enzyme secretions. Ex: dwarf cultivars can be treated with GA and grow to normal heights – indicates dwarf species lack normal levels of GA	Gibberellins (GA) Gibberellic Acid
Gibberellins are Used commercially in:	1 Increasing fruit size of seedless grapes 2 Stimulating seed germination & seedling growth 3 Promoting male flowers in cucumbers for seed production. 4 Overcoming cold requirements – for some seed, application of GA foregoes the cold requirements (some seed require to be frozen or placed in the refrigerator for a period of time before they will germinate).
Promotes cell division Found in all tissues with considerable cell division. Ex: embryos (seeds) and germinating seeds, young developing fruits Roots supply upward to the shoots. Interact with auxins to influence differentiation of tissues (may be used to stimulate bud formation). (cytokinesis)	Cytokinins
As roots begin to grow actively in the spring, they produce large amounts of cytokinins that are transported to the shoot, where they cause the dormant buds to become active and expand. Tissue cultures use cytokinins to induce shoot development Cytokinins may slow or prevent leaf senescence (leaf ageing or leaf fall).	.
Gaseous hormone Produced in the actively growing meristems of the plant; in senescing, ripening or ageing fruits; in senescing (ageing or dying) flowers, in germinating seeds and in certain plant tissues as a response to bending, wounding or bruising. as a gas, diffuses readily throughout the plant. May promote leaf senescing and abscission (leaf fall). Increases female flowers in cucumbers (economically - will increase fruit production). Degreening of oranges, lemons and grapefruit – ethylene gas breaks down chlorophyll and lets colors show through.	Ethylene
Abscisic Acid (ABA) -Widespread in plant body – moves readily through plant. -ABA appears to be synthesized (made) by the leaves. -promotes leaf detachment, induces seed and bud dormancy, and inhibits germination. -Involved with leaf and fruit abscission (fall), onset of dormancy in -seeds and onset of dormancy (rest period) in perennial flowers and shrubs -is effective in inducing closure of stomata in leaves, indicating a role in the stress physiology in plants. ex: increases in ABA following water, heat and high salinity stress to the plant)	Inhibitors