Download Tropisms Growth inhibitor found in plants. It is a plant growth

Tropisms
Growth inhibitor found in plants. It is a plant growth regulator (plant
hormone) that promotes dormancy and leaf fall, inhibits longitudinal
growth and when a leaf begins to wilt it causes the stomata to close
rapidly.
abscisic acid
Leaf fall, resulting from the dissolving of the cementing material
between thin-walled plant cells at the base of the petiole and stem.
abscission
A chemical that is a plant growth regulator or a plant growth
hormone (e.g. IAA), produced in the meristematic tissue of shoots,
roots, young leaves and developing seeds. It stimulates cell
elongation and cell division in plants. It is involved in tropic
responses, apical dominance, shoot and root growth and fruit
formation. It is produced in one part of a plant but its action is in
another.
auxin
The growth response of a plant to chemicals, e.g. fertilisers.
chemotropism
A sheath containing the first leaf (shoot or plumule) of a germinating
cereal grain.
coleoptile(s)
Plant growth hormones, which increase the rate of cell division and
inhibit aging of green tissues in plants.
cytokinins
Plant growth substance used to promote ripening of some fruits (e.g.
bananas, melons, tomatoes), de-greens others (e.g. oranges, lemons
ethene / ethylene
and grapefruits) and promotes abscission and inhibits longitudinal
growth.
The growth response of a plant to gravity.
geotropism
Plant growth promoter which stimulates cell elongation and
germination.
gibberellin
The growth response of a plant to water.
hydrotropism
A plant growth hormone (auxin) that stimulates cell elongation.
IAA (indoleacetic
acid)
A plant growth regulator which promotes cell division and the
development of buds and roots and inhibits ageing in the higher
plants.
kinin
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The growth response of a plant to light, caused by the higher
concentration of the plant growth regulator IAA (indoleacetic acid,
an auxin) on the darker side of the plant shoot. This promotes cell
elongation on that side and the shoot grows towards the light as a
result.
Chemicals produced in the meristematic regions and transported
through the vascular system of plants. They affect the rate of growth
(cell division) or development of plants when they are in very low
concentrations.
A chemical which kills certain types of weeds only, e.g. any weed
killer containing 2,4-D will kill only broad leaved plants (e.g. daisy,
dandelion, clover, plantain, etc.) in lawns but will not harm the grass.
phototropism
plant growth
regulators
selective weed
killer
Any change in the environment (internal or external) that causes a
cell or organism to respond.
stimulus: (plural =
stimuli)
The growth response of a plant to touch, e.g. tendrils.
thigmotropism
The growth of part of a plant as a result of an external stimulus (e.g.
light, gravity, etc.) promoting the production of an auxin.
tropic response
The growth response of part of a plant to an external unidirectional
stimulus. Can be positive (growing towards the stimulus) or negative
(growing away from the stimulus).
tropism
Light shining on an object from one side only.
unilateral light
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