A normal chromosome has the gene sequence A B C D E F G H I
       A normal chromosome has the gene sequence A B C D E F G * H I which of the following represents a tandem duplication?  A B C D D C B E F G * H I  none of the Above  A B C D E F D E F G * H I  C D E F G * H I  A B C  D E F G * H B A B C D E 
  
  Solution
Answer:
ABCDEFDEFG.HI
Explanation:
The occurrence of two identical sequences, one following the other, in a chromosome segment is called tandem duplication.
ABCDEFDEFG.HI---Tandem duplication
ABCDDCBEFG.HI—Reverse tandem duplication.

