Page 58 - Biology - XII
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Conclusion
          The dominant traits of pea seeds are more in number than the recessive
          traits. Mendelian ratios can be confi rmed or studied only after obtaining the
          seeds of second generation.

          Precautions
           1.  Study the traits studied by Mendel.

           2.  Study more than one trait at a time.                                          Gregor Johann Mendel
           3.  Study should be done for two generations at least for deduction and
              interpretation of laws of Mendel/Ratios.


                                                        VIVA VOCE


           Q1.  What term is given to the traits that follow the Mendelian laws of inheritance?
          Ans.  Mendelian traits
           Q2.  Diff erentiate between the off springs (F  and F ) of monohybrid cross.
                                                          1
                                                                  2
          Ans.  Monohybrid F  off springs—All are hybrids.
                                1
                 Monohybrid F   off springs—Hybrids  are  crossed  and  result  in  separation  of  dominant,  recessive,
                 and hybrids.   2

           Q3.  Why is the dominant trait represented before the recessive trait?
          Ans.  It is customary to represent the dominant trait fi rst.

           Q4.  What is the explanation given by the law of segregation?
          Ans.  It explains that the two alternative factors for each character separates, and segregation happens
                 during the formation of gametes.

           Q5.  What is a cross?
          Ans.  The process in which a pair or more pairs of contrasting traits are studied.
           Q6.  Mention the laws of inheritance?
          Ans.  (i) Law of dominance (ii) Law of segregation and (iii) Law of independent assortment

           Q7.  Why did you use seed samples for the study of Mendelian ratios?
          Ans.  Seeds were used for the study because they exhibit a large variety of traits.
           Q8.  Who was Mendel?
          Ans.  He  was  a  monk.  Now,  regarded  as  Father  of  Genetics,  as  he  formulated  the  laws  of  genetic
                 inheritance through various experiments with Pisum sativum plant.

           Q9.  What is dominant trait?
          Ans.  The trait that expresses itself in F  generation is dominant.
                                                   1
          Q10.  What is Mendelian ratio?
          Ans.  The ratio of traits that follow the ratio given by Mendel is called Mendelian ratio.
          Q11.  Why do some traits (characters) appear in large numbers (ratios) than the other corresponding
                 ones?
          Ans.  Because they are the dominant traits.




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