Yogy's biology

  11 Enhancement of Food Production - part 03 - Tissue culture Tissue culture : Is actually a collection of different techniques.  T echnique of plant biotechnology.  Here, isolated cells, tissues, organs are grown  ‘in vitro’  on a solid/ liquid nutrient medium, under aseptic and controlled conditions of light, humidity and tempreature, for achieving different objectives. Part of plant used in tissue culture is called  explant .  Plant tissue culture is based on  principle of Totipotency  which is an inherent ability of living plant cell to grow, divide, redivide and give rise to a whole plant.  Haberlandt  (1902 for the first time conceived this idea and developed the concept of in vitro cell culture ( plant morphogenesis ). Medium contains all essential minerals, sources for carbohydrates, proteins and fats, water, growth hormones, vitamins and agar (for callus culture).  Most commonly preferred medium for tissue culture is...

  11 Enhancement of Food Production - part 02 - Hybridization and its technique A. Hybridization and its technique : It is the  cheif method  that offers greater possibilities in the crop improvement than other methods.  Only effective means of  combining together the desirable characters of two or more varieties. Can create  new genetic combinations  of already existing characters and  new genetic variations.  It also exploits and utilizes  hybrid-vigour. Hybridization can be -  intravarietal intervarietal  (between two varieties of the same species) interspecific  (between two species of the same genus) and intergeneric  (between two genera of the same family).  As parental plants are distantly related, such crosses are also called  wide/ distant crosses.  Interspecific and intergeneric hybrids are seldom to occur in the nature. Main steps of the plant breeding program (Hybridization)  : 1. Colle...

  11 Enhancement of Food Production - part 01 - Improvement In Food Production, Plant breeding Improvement In Food Production : Food is one of the  basic needs  as it gives us energy for everything.  It keeps us alive, strong and healthy. It can be defined as any thing solid or liquid, which when swallowed, digested and assimilated in the body, keeping us well.  It is organic, energy rich, non-poisonous, edible and nourishing substance. Green plants synthesize their own food through  photosynthesis .  But animals including  humans  can not synthesize their food on their own, hence are dependent on plants directly. The famine is responsible for dearth of food, besides the rapid and dramatic increase in world population over the time.  To meet the increasing demand for food, there is need for improvement of food production, both quantity wise and quality wise (nutritive). Plant breeding and animal breeding  help us to increase the foo...

  10 Human Health and Diseases - part 11 - Drugs Abuse Drugs Abuse : Surveys and statistics show that use of drugs and alcohol has been on the rise especially among the youth.  This is really a cause of concern as it could result in  many harmful effects.  Proper education and guidance would enable youth to safeguard themselves against these dangerous behaviour pattern and follow healthy lifestyle.  The drugs, which are commonly abused, are  opioids, cannabinoids and alkaloids of coca. a. Opioids : These drugs binds to  opioid receptors  present in  central nervous system  and gastrointestinal tract.  Heroin , otherwise called  smack  is chemically  di-acetyl morphine.  It is extracted from  latex  of poppy plant  Papaver somniferum.   Heroin is depressent and slows down the activity of body. b. Cannabinoids : Interact with receptors present in brain.  Inhalation and ingestion of these su...

  10 Human Health and Diseases - part 10 - Addiction Addiction  : This is a complex condition characterised by  compulsive use of substance despite of its harmful consequences.  Addiction may involve the use of substances  (drugs)  such as  alcohol, opioids, cocaine, nicotine  and others or behaviours such as gambling. There is scientific evidence that the addictive behaviours share  key neurobiological features.   They intensely involve brain pathways of reward and reinforcement, affecting motivation, which involve the  neurotransmitter dopamine .  It is important to know that the  neurological changes are reversible  after the substance-use or behaviour is discontinued. Addiction overall result in the impairment of physical, physiological and psychological functions of the body. Causes of substances abuse during Adolescence : Insufficent parental supervision and monitoring. Lack of communication between child and pa...

  10 Human Health and Diseases - part 09 - Adolescence Adolescence : Period of begining with the  appearance of secondary sexual characters  and the termination with ceassation of somatic i.e.  body growth.  Regarded as a transitional stage of physical and mental development of child occurring between puberty and the legal adulthood  between 10 to 19 years of age  where individual is no loger a child but not yet an adult. Adolescence in fact is a phase rather than fixed time period in the life.  It is a phase of -  Development on many fronts like sexual and reproductive maturity Mental development,  Adult identity and  Transition from socioeconomic and emotional dependant to relative independence. Stages of Adolescence : Adolescents are defined are individual 10 to 19 year age group.  The government of India in its  National youth policy  defines adolescents as  13-19 years.  Adolescents is divided in three ...