XII BIOLOGY NOTES 2021-2022

                                   

TOPIC NO.	TOPIC NAME	DOWNLOAD
1	Reproduction in Lower and Higher Plant	DOWNLOAD
2	Reproduction in Lower and Higher Animals	DOWNLOAD
3	Inheritance and Variation	DOWNLOAD
4	Molecular Basis of Inheritance	DOWNLOAD
5	Origin and Evolution of Life	DOWNLOAD
6	Plant Water Relation	DOWNLOAD
7	Plant Growth and Mineral Nutrition
8	Respiration and Circulation	DOWNLOAD
9	Control and Co-ordination	DOWNLOAD
10	Human Health and Diseases	DOWNLOAD
11	Enhancement of Food Production
12	Biotechnology
13	Organisms and Populations
14	Ecosystems and Energy Flow
15	Biodiversity. Conservation and Environmental Issues

07. Plant Growth and Mineral Nutrition

Introduction :-

         Growth is one of the characteristic features of living organisms. Growth as a phenomenon has two aspects viz. quantitative and qualitative. 
        Quantitative aspect :- It is about the  increase in the length, breadth, size, volume, body mass or dry weight and number of cells. Growth as  a quantitative  change is a final end product of successive metabolism.
       Qualitative aspect :- It is  about the change in the nature of growth where development is an ordered change or progress while differentiation leads to higher and more complex state. 
      Growth thus can be defined as permanent, irreversible increase in the bulk / mass of an or-ganism, along with the change of form.
       In multicellular (vascular) plants, growth is indeterminate and occurs throughout the life indefinitely.

Root and stem show indefinite or indeterminate growth.
While, in organs like leaves, flowers and fruits, growth is determinate. i.e. they grow up to certain genetically destined size.
In unicellular plants, growth  is  uniform  and  determinate.

     Growth is restricted to some specific region called meristems.  Meristems are of three types based on location viz. Apical, Intercalary and Lateral.