Mutiple choice questions based on restriction endonucleases

1.     Type I restriction endonuclease cleaves
a) Within the recognition sequence
b) both side of the recognition sequence
c) 20 to 30 bp away from the recognition sequence
d) 1000bp away from the recognition sequence

2.     Which of the following is not true about type II restriction endonuclease?
a) Cleavage and Methylation are by different enzymes
b) In this case the recognition sequence is asymmetric
c) It cleaves within the recognition sequence
d) It can’t cleave at methylated sequences

3.     Restriction endonucleases can recognize
a) Tandem repeats
b) Pallindromic sequences
c) both
d) No sequence specificity

4.     Which of the sequence will Dcm enzyme methylate?
a) GATC
b) GAATC
c) CCGTT
d) CCAGG

5.     Which of the following enzyme are isoschizomer?
a) SphI and BbuI
b) Not1 and HindIII
c) SmaI and XmaI
d) Pst1 and Sma1

6.     Restriction enzymes cleave the bond by which type of reaction?
a) S_N1
b) S_N2
c) S_E1
d) S_E2

7.     Which of the following enzyme are neoschizomer?
a) SphI and BbuI
b) Not1 and HindIII
c) SmaI and XmaI
d) Pst1 and Sma1

8.     If all the nucleotides are present with equal frequencies and at random, what are the chances of having a particular four nucleotide long motif?
a) 1/256
b) 1/64
c) 1/16
d) 1/8

9.     Which of the following enzymes are isocaudomer?
a) SphI and BbuI
b) Not1 and HindIII
c) Sau3A and BamH1
d) Pst1 and Sma1

10.  Zinc-finger nucleases is

a)     natural restriction enzyme

b)    type of polymerase enzyme

c)     artificial restriction enzyme

d)    type of helicase enzyme

Answers: 1. D, 2. B, 3. B, 4. D, 5. A, 6. B, 7. C, 8. A, 9. C, 10.  c