Writes notes on following :
(a) Senescence (b) Abscission
(c) Quiescence (d) Vivipary.
(a) Senescence : Senescence is the process of ageing in plants. It is the period between maturity and death.
(b) Abscission: It is the natural falling of leaves, foliage branches, fruits, floral parts etc.
(c) Quiescence : It is the suspension of growth due to external factors. It is a period during which development is suspended.
(d) Vivipary : It is the process when seeds germinate inside fruits which are still attached to the mother plant.
Auxins are of two types :
(1) Natural auxins : These are naturally occuring auxins, isolated from plants and are regarded as phytohormones e.g. IAA. NAA etc.
(2) Synthetic auxins : These are synthesized by artificially e.g. IBA 2,4-D etc.
Auxin was isolated by F.W. Went from tips of coleoptiles of oat seedling.