Bacteria can protect themselves from getting infected by bacteriophages as they synthesize:
1. Methylase
2. Ligases
3. Plasmids
4. Endonucleases

‘Competence’ can be induced in a bacterium by treating them with:
1. Polyethylene glycol
2. A specific divalent cation
3. Colchicine
4. Alkaline phosphatase

Match the following enzymes with their functions:
 

Select the correct option from the following:

DNA fragments are 
1. Negatively charged
2. Neutral
3. Either positively or negatively charged depending on their size.
4. Positively charged. 

Which of the following is not a feature of the plasmids? 
1. Independent replication
2. Circular structure
3. Transferable
4. Single-stranded 

The cutting of DNA at specific locations became possible with the discovery of 
1. Ligases
2. Restriction enzymes
3. Probes
4. Selectable markers 

Which vector can clone only a small fragment of DNA? 
1. Bacterial artificial chromosomes
2. Yeast artificial chromosomes
3. Plasmid
4. Cosmid

Which of the following are used in gene cloning?
1. Lomasomes
2. Mesosomes
3. Plasmids
4. Nucleotides 

Which one of the following palindromic base sequences in DNA can be easily cut at about the middle by some particular restriction enzyme?
1. 5’______CACGTA_______3’
3’______CTVAGT_______5’
2. 5’______CGTTCG_______3’
3’______ATGGTA_______5’
3. 5’______GATATG_______3’
3’______CTACTA_______5’
4. 5’______GAATTC_______3’
3’______CTTAAG_______5’

Restriction endonucleases are enzymes which 
1. Remove nucleotides from the ends of the DNA molecule.
2. Make cuts at specific positions within the DNA molecule.
3. Recognize a specific nucleotide sequence for binding of DNA ligase.
4. Restrict the action of the enzyme DNA polymerase.