Think Work VM Knowledge

  Practical Notebook Biology Standard XII Biology  Answeres Practical Notebook Standard XII Class-12th science Click here download in PDF 10. Dissect and display floral whorls.  Dissect another and take T.S.  or V.S.  of the ovary to show pollen grains and locules of the ovary, respectively.    Aim:  To dissect given flowers to study and display different whorls.  Dissect anther and ovary to show a number of locules (chambers).   Requirements: -  Flowers such as Brassica or Hibiscus.  Forceps, razor blade, slides, two needles, coverslips, dissecting microscope, paper, etc.  Ced  Procedure: -  Observe different floral whorls such as calyx, corolla, androecium, and gynoecium.  Take out each floral whorl carefully and arrange them in proper ascending order on white paper.  Count the members of each whorl and also note down, if there is cohesion or adhesion between the members of the same whorl or different whorls.  Mount the anthers on the slide and observe them under a lens or dissectin

  Practical Notebook Biology Standard XII Biology  Answeres Practical Notebook Standard XII Class-12th science Click here download in PDF 11. To study wing shape and eye color in Drosophila.   Aim:  To study the genetic variation of traits in Drosophila melanogaster.  Requirements: Glass jar, petri dish, banana pieces, muslin cloth, bell jor, slide, coverslips grated series of school, fine, DP%, etc. Procedure L Preparation of culture beds:  Peel the ripe banana fruit.  Discard the skin and mash the fruit into a soupy pulp.   Take a clean sterilized glass jar or Petri dish and place the banana pulp in it.   Add a few grains of yeast.   Keep a small blotting paper to absorb excess moisture from the pulp and also to provide a substratum for the pupation of the larvae.   Many culture beds can be prepared by the above method for the different varieties of a fruit fly.  II The culturing of Drosophila  The pulp in the culture beds attracts the Drosophila.  Cover the culture beds with a bell