Plant Growth and Development
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Elongation phase: It occurs in cells proximal (just next, away from the
tip) to the meristematic zone. The cells have increased vacuolation, size
and new cell wall deposition.
Maturation phase: It occurs in the cells further away from the apex, i.e.,
more proximal to the phase of elongation. The cells attain maximal size
in terms of wall thickening and protoplasmic modifications.
GRØWTH RÅTËS
It is the increased growth per unit time.
The growth rate may be arithmetic or
geometrical.
ÅRÏTHMËTÏÇ GRØWTH
In this, following mitotic division, only one
daughter cell continues to divide while
the other differentiates & matures.
The simplest expression of arithmetic
(growth is exemplified by a root elongation at a constant rate.
On plotting the length 'L' of the organ against time 't', a linear curve is
obtained.
Mathematically, it is expressed as
Lt = L0 + rt
Lt = length at time ‘t’
L0 = length at time ‘zero’
r = growth rate / elongation per unit time.
Height of the plant
Time