1.  The genotype  - XXY ?      a) is impossible to produce             b) appears female             c) appears male
                                               d) non-viable and dies at birth                   e) none of the above is correct


     2.  In a cross of pure breeding genetics lines the recessive trait?

             a) is seen only in the F-1 generation                                   b) masks the expression of the dominant trait

             c) is expressed by using "CAPITAL" letters in crosses   d) occurs in 75% of the F-2 progeny

             e) none of the above is correct


 413. The heterogametic sex?

             a) has sex chromosomes of dissimilar morphology            b) is always XX               c) is always male

             d) more than one of the above is correct                             e) none of the above is correct


4.  The gene  a  is 5 mu from from the gene  b, and the gene  c  is 3 mu from the gene  a, while the
gene  b is 8 mu from the gene  c.   The most likely order for these genes is?

         a) abc                  b) bca                  c) cab               d) cba               e) none of these


5.  A recombination frequency of 11% between linked genes gives a relative map distance between
the genes?         a) of 11 map units                         b) 5.5 map units                    c) of 22 map units
                             d) 11 genes                                   e) none of these


     6.  Which of the following Human diseases is caused by a chromosomal aberration?

             a) red/green color blindness     b) Tay-Sachs disease     c) Down Syndrome     d) Sickle Cell Anemia
             e) none of the above is a correct choice