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  Practical Notebook Biology Standard XII Biology  Answeres Practical Notebook Standard XII Class-12th science Click here download in PDF To study the prepared pedigree charts of genetic trolling of the tongue, widow's peak, blood groups, and color blindness  Male Female Introduction:  A pedigree is a list of ancestors showing genetic relationships between members of a family.  A record of inheritance of certain genetic traits for two or more generations is presented in the form of a family tree or a diagram is called a pedigree chart.  The study of pedigree charts provides a strong tool, which is used to trace the inheritance of a specific trait, abnormality, or disease family.   In a pedigree charts specific that are used, are indicated below:  Mating symbols and children 1 bey I girl ( in order of beth ) Duygotic ( identical twin ) Monorygotic ( identical twins ) Sex unspecified OOD Number of children of sex indicated Affected individuals  Heterorypotes for autosomal recessive

  Practical Notebook Biology Standard XII Biology  Answeres Practical Notebook Standard XII Class-12th science Click here download in PDF 9. Demonstration of hybridization technique  Introduction Hybridization is one of the methods of crop improvement undertaken to combine the and female parents.   The technique involves the following steps:  desired, useful characteristics from two different pure varieties of plant species, selected as male & Collection of pollen grains  (Anthesis): Pollen grains from the flower of the selected male parent are collected in sterile paper bags and are stored in clean and dry vials at a cool place.  The collection is done in the early hours of the morning.  Day, date, and time of Anthesis are recorded.  b.   Emasculation:  It is the removal of young anthers of the stamens in the plant selected as the female parent having bisexual flowers, well before anthesis i.e. formation of pollen grains.  The bisexual flower of a female parent is emasculated. Bu

  Practical Notebook Biology Standard XII Biology  Answeres Practical Notebook Standard XII Class-12th science Click here download in PDF 8. Study of plants found in xerophytic and aquatic conditions/habitats.  And comment on their adaptations  Introduction:  Adjustment (acclimatization) of plants and animals for their survival and perpetuation, to their environment by means of special structures or functions, is known as adaptation The plants that can grow and survive in deserts, dry conditions of soil, and high temperature, are called xerophytes.  All xerophytes show adaptations to reduce the loss of water due to transpiration.  Some xerophytes show the presence of stored mucilage in the plant parts that help in retaining water.  Some plants have latex, that helps retain water and seal the place of injury.  E.g.  Euphorbia, Calotropis, Acacia, Opuntia.   The plants that grow in abundance of water are, called hydrophytes.  They are generally adapted to remain buoyant and avoid the dec

  Practical Notebook Biology Standard XII Biology  Answeres Practical Notebook Standard XII Class-12th science Click here download in PDF https://drive.google.com/file/d/10NrtEg6k0Hh8ttkenvZvI2EzFqZN8vPr/view?usp=sharing 7. Study of meiosis in onion flower bud with the help of permanent slides.  Aim:  To study and identify different stages of meiosis.  Principle 1 Meiosis is a special type of cell division that occurs in the diploid reproductive or germ tissue (cells).  It is a reduction division that results in the formation of four haploid daughter cells each receiving half of the total number of chromosomes than those present in the mother cell from which it is produced Observation For the preparation of meiosis slides, generally, anther of Lily or Onion is used.  Meiosis can be studied with the help of stained permanent slides of T. S. of the anther.  Permanent slides should be observed under the high power of a compound microscope.  Meiosis is a process that occurs in two steps vi

Practical Notebook Biology Standard XII Biology  Answeres Practical Notebook Standard XII Class-12th science Click here download in PDF T.S.  Testis: Date Internal structure of testis shows the presence of tunica albuginea and seminiferous tubules.  Testis 6. Study of T. S. testis, T. S. ovary, and V. S. of blastula, through permanent slides.  Is externally covered by fibrous connective tissue called tunica albuginea.  It is internally covered by tunica vascularis formed by capillaries and externally by an incomplete covering called tunica vaginalis.  Seminiferous tubules are lined by cuboidal germinal epithelial cells.   It shows different stages of spermatogenesis lic spermatogonia, primary and secondary spermatocytes, spermatids, and sperms.  Few large pyramidal cells are present interrupting germinal epithelia are nurse cells or Sertoli cells.  Sperm bundles get attached to Sertoli cells with their heads.  The function of Sertoli cells is to provide nourishment to the sperms till

  Practical Notebook Biology Standard XII Biology  Answeres Practical Notebook Standard XII Class-12th science Click here download in PDF 5. Study of V. S. of anatropous ovule through a permanent slide / relevant chart.   Ovule (megasporangium) is enclosed in the ovary.   There may be one or many ovules in an ovary.   Alm:  Study of anatropous ovule and functions of its various parts.  .  The ovule in which micropyle, chalaza, and funicle are not in one straight line and integuments run parallel to funicle is called as anatropous ovule.  It is also called an inverted ovule and is the most common type of ovule, in angiosperms, The ovule shows two main parts - body and funicle.  Body The body shows two integuments originating from the base of the ovule reaching up to the tip of the ovule.   The tip shows a small cleft, left by two integuments called a micropyle.  The integuments enclose a mass of fertile, parenchymatous, diploid cells called nucellus.  There is only one fertile cell loc

  Practical Notebook Biology Standard XII Biology  Answeres Practical Notebook Standard XII Class-12th science Click here download in PDF 2. Separation of plant (photosynthetic) pigments by paper chromatography Aim:  Separation of plant (photosynthetic) pigments by paper chromatography.  The plants show the presence of many pigments.  The different photosynthetic pigments present in the leaf cells are chlorophylls, carotenes, and xanthophylls.  These photosynthetic pigments can be separated using the technique of paper chromatography.  Principle The separation of solutes (chloroplast pigments) is based on the liquid-liquid partitioning of pigments in paper chromatography.  The partitioning takes place between the solvent (water) molecules (static phase) adsorbed to the cellulosic matter of the paper (capillary action organic (mobile) phase.)  Requirements -  Chromatography chamber, chromatography paper (Whatman's filter no.1), pestle - mortar, capillary tube, muslin cloth, suitabl