Notes Ghar

  CHAPTER-01 REPRODUCTION IN ORGANISMS Reproduction is a biological process of formation of new offsprings from the pre-existing organism.Reproduction becomes a vital process without which species cannot survive for long It ensures continuity of species generation after generations as older individuals undergo senescence and ultimately they die. Life span  - • The period from birth to the natural death of an organism represents its  life span . Life span of organisms varies from few days (Butterfly-1to 2 weeks) to thousands of years (Banyan tree). Types of Reproduction : Based on whether there is one or two organisms taking part in the process of reproduction ASEXUAL REPRODUCTON SEXUAL REPRODUCTION When the offspring is produced by single parents with or without the involvement of gamete formation, the reproduction is called  asexual reproduction . When two parents (opposite sex) participates in reproduction process and also involves the fusion of male and female gametes, it is called 

CHAPTER-12 MINERAL NUTRITION Mineral nutrition is the study of source, mode of absorption, distribution and metabolism of various inorganic substances (minerals) by plants for their growth, development, structure, physiology and reproduction. Methods to study the Mineral Requirement of Plants Hydroponics  is the technique of growing plants in nutrient solution in complete absence of soil. This method is used to determine the nutrients essential for plants. In this method plant is cultured in soil-free, defined mineral solution. These methods require  purified water  and  mineral nutrients . Essential elements are identified and their deficiency symptoms are discovered by hydroponics methods. It is also used for commercial production of vegetables, like tomato and cucumber. Essential mineral nutrients-  About 65 elements are found in different plants. Following criteria is used to determine the essentiality of an element. Element must be absolutely necessary for the normal growth and re

CHAPTER-11 TRANSPORT IN PLANTS Plant transport various substances like gases, minerals, water, hormone and organic solutes to short distance (one cell to another) or long distance as water from roots to tips of stem. Long distance transport occurs through vascular system, xylem and phloem called  translocation  through mass flow. The direction of translocation may be unidirectional as in case of water and multidirectional as in minerals and organic solutes. Simple Diffusion- Movement by diffusion is passive and slow along the concentration gradient through permeable membrane. No energy expenditure takes place. It occurs in liquid and gases. Rate of diffusion are affected by gradient of concentration, permeability of membrane, temperature and pressure. Facilitated Diffusion- Lipid soluble particles easily pass through cell membrane but the hydrophilic solutes movement is facilitated. For facilitated diffusion, membrane possesses aquaporins or water channels.  Aquaporins  are membrane pr