Life Science(Biology)

1. What is "totipotency"?            The ability of a plant cell to perform all the activities of development like a zygote to develop into a complete plant is termed as totipotency. Haberlandt ,1902 first demonstrated totipotency by  in vitro technique. 2. How do haploid plants produced?       Haploid (n) plants are obtained by induction of embryogenesis during Anther and Pollen Culture.  3. How are   haploid plants made Homozygous diploid  ?                                          2/2020 BotH,TU   The chromosome set of haploid pollen grains are first doubled by mutagenic chemicals like colchine (0.5% for 24-48 hr.). Then homokaryotic fusion resulted into production of  homozygous diploid plants ( Vasil and Nitsch,1975). 4. What is Anther Culture?Describe the process with factors.      Th...

   Detection of unknown sugar sample solution  General Test:1 1.Benedict's Test Experiment  3ml sample solution and 2-3 ml Benedict's qualitative reagent are mixed in a dry clean test tube and boiled for 5 minutes. Observation  The mixture solution turns green, yellow and finally red. Inference  The supplied sample is of reducing sugar.  The red ppt. is Cu2O (I). Reactions : Reducing sugar+alkali—>Enediols Enediols+2 Cu2+---> 2Cu+ + acidic sugar 2Cu+ + 2OH– —-> 2CuOH 2CuOH +Heat —> Cu2O (red ppt) +H2 O General Test   2.Barfoed's Test Experiment  1 ml (5 drops) sample solution and 3 ml Barfoed's reagent ( a soln of cupric acetate and acetic acid) are mixed in a test tube and boiled in a boiling water bath for 3 minutes. Observation  A reddish ppt.is formed. Inference  The reducing sugar is a monosaccharide since ppt is formed within 3 minutes. Reaction : R–CHO + 2 Cu2+ +2H2O—-> R–COOH + Cu2O + 4H+ Confir...