Synthetic auxins are used to get rid of dicot, such as Dandlions and thistles in areas reserved for monocots such as grain fields. A dicot responds to unnaturally high concentrations of auxins by growing rapidly and then die; whereas monocot, remains unaffected by the treatment.
Quantitative comparisons between the growth of living system can be made in two ways :
(i) By measuring and comparing the total growth per unit time. This is called the absolute growth rate.
(ii) The growth of the given system per unit time expressed on a common basis, e.g., per unit initial parameter. This is called the relative growth rate.
What structural changes do the cells undergo during differentiation as tracheary elements?
The cells undergo the following structural changes during the process of differentiation as tracheary elements.
i. The cells lose their protoplasm to form tracheary elements.
ii. They also develop a very strong, elastic,
lignocellulosic secondary cell walls, to carry water to long distances even under extreme tension.