Question

Read the sources given and answer any four from the questions given below:

It is a well-known fact that every individual has a unique DNA fingerprint or DNA profile. It is same for each and every cell of the body. It is an ideal way to distinguish one individual from another. DNA fingerprinting is used to analyse DNA present in the biological materials like body fluids (saliva, semen) or in the cells like WBCs, hair roots, bone or any cell that contains nucleus. DNA of an individual contains various types of segments like (i) some code for proteins, (ii) some have regulatory functions, (iii) some are intervening sequences that do not code for proteins called introns and (iv) some are short repetitive DNA sequences. For DNA fingerprinting, these short repetitive nucleotide sequences are of importance as these differ at certain sites from person to person. These are called as Variable Number Tandem Repeats (VNTR). The VNTR of two persons may be of same length and sequence at certain sites but vary at other sites. In DNA fingerprinting, DNA is first extracted from the cells and then divided into fragments by restriction enzymes. The fragment are then separated according to their size by electrophoresis. The separated fragments form a pattern of parallel bands specific to an organism.

1. For DNA fingerprinting, DNA can be taken from
   1. only body fluids
   2. only body cells
   3. only living cells
   4. both (a) and (b)
2. DNA of an individual contains various types of segments like
   1. some code for proteins and fats
   2. some do not code for proteins
   3. some code for very long repetitive DNA sequences
   4. both (a) and (b)
3. Importance of VNTR is that
   1. two people can have same length of VNTR
   2. VNTR vary at some sites in two people
   3. these are made of short nucleotides
   4. these are repetitive in nature
4. DNA extracted from a cell is divided into fragments by
   1. DNA polymerase
   2. introns
   3. ligases
   4. restriction enzymes
5. During electrophoresis the DNA fragments
   1. get aligned according to their weight
   2. get separated into VNTR
   3. get aligned according to their size
   4. get separated into one line

Answer 1

1. both (a) and (b)
2. some do not code for proteins
3. VNTR vary at some sites in two people
4. restriction enzymes
5. get aligned according to their size