Blunt and Sticky Ends

Q.

What is restriction mapping???

Q.

Read statement a-d. Which two of them have mistakes?
(a) First transgenic buffalo, Rosie produced milk which was human alpha lactalbumin enriched.
(b) Restriction enzymes are used in isolation of DNA from other macromolecules.
(c) Downstream processing is one of the steps of r-DNA technology.
(d) Disarmed pathogen vectors are also used in transfer of r-DNA into the host.

Q.

What is the difference between Type 1 and Type 2 restriction enzymes?

Q.

Why do restriction enzymes not cut their own DNA?

Q. Which of the following restriction enzymes produce blunt ends in DNA?

1. BamHI
2. EcoRI
3. HaeIII
4. Alu I

Q.

Why are Type 2 restriction enzymes used for cloning?

Q.

What type of restriction enzyme is EcoRI?

Q. In the diagram of pBR322, which identifies components correctly?

1. rop–reduced osmotic pressure
2. Hind III, EcoRI–selectable markers
3. amp${}^R$, tet${}^R$–antibiotic resistance genes
4. ori–original restriction enzyme

Q.

Genomic DNA is digested with Alu I, a restriction enzyme which is a four base - pair cutter. What is the frequency with which it will cut the DNA assuming a random distribution of bases in the genome?

1. 1/4

2. 1/24

3. 1/256

4. 1/1296

Q. Choose the incorrect statement with reference to restriction enzymes.

1. The specific palindromic sequence which is recognized by EcoRI is
   5′–CTTAAG–3′
   3′–GAATTC–5′
2. Restriction enzymes may cut the strands of DNA a little away from the centre of the palindrome sites
3. Restriction endonucleases are used in genetic engineering to form ‘recombinant’ molecule of DNA
4. These enzymes cut the strands of DNA between the same two bases on the opposite strands

Q.

Which of the following restriction enzymes produces blunt ends?

1. Xho I

2. Hind III

3. Sal I

4. EcoR V

Q. Which of the following is a correct statement regarding sticky end fragments produced by restriction enzymes?

1. They are produced by all restriction endonucleases
2. In recombinant DNA technology blunt ends are more preferred as they have overhangs
3. The stickiness of the end facilitates the action of DNA polymerase
4. They are named sticky ends because they form hydrogen bonds with their complementary cut counterparts

Q. How many of the following statements regarding restriction enzymes are correct?
A. They generally recognise palindromic nucleotide sequences.
B. They are endonucleases.
C. They are isolated from viruses.
D. A particular restriction enzyme produces the same kind of sticky or blunt ends in any DNA molecules.

1. 1
2. 2
3. 3
4. 4

Q. In order to isolate the DNA with the gene of interest from an animal cell, it needs to be in pure form, free from other macromolecules. The DNA molecules intertwine around histone proteins. Which of the following enzyme treatments will help to purify the DNA from the associated proteins?

1. RNase
2. Protease
3. Chitinase
4. DNase

Q. How many of the following statements regarding restriction enzymes are correct?
A. They generally recognise palindromic nucleotide sequences.
B. They are endonucleases.
C. They are isolated from viruses.
D. A particular restriction enzyme produces the same kind of sticky or blunt ends in any DNA molecules.

1. 1
2. 2
3. 3
4. 4

Q. Some of the steps followed for molecular diagnosis of a pathogen are given. Identify their correct sequence from the options given below.
I. Electrophoresis of DNA fragments
II. Hybridisation with DNA probe
III. Digestion of DNA by restriction endonucleases
IV. Autoradiography
V. Transferring of DNA fragments on nitrocellulose membrane

1. III – I – II – V – IV
2. III – I – V – II – IV
3. I – V – III – II – IV
4. I – III – V – IV – II

Q. PCR : _____I_____
Gel electrophoresis : _____II_____

1. I - Amplification of DNA molecule,
   II - Separation of DNA molecules on the basis of size
2. I - Separation of DNA molecules on the basis of size,
   II - Amplification of DNA molecule
   
3. I - Cleavage of DNA molecule,
   II - Amplification of DNA molecule
   
4. I - Separation of DNA molecules on the basis of size,
   II - Cleavage of DNA molecule

Q. Restriction fragment length polymorphisms (RFLPs)

1. can be subjected to gel electrophoresis
2. are the basis for DNA fingerprints
3. identify individuals genetically
4. all of these

Q. During the process of making tobacco plant resistant to nematode, each siRNA complexes with certain ribonucleases to form a complex called ______.

1. Crystal violet iodine complex
2. RNA induced silencing complex
3. DNA induced silencing complex
4. Nicotine complex

Q. Which of the following is not a source of restriction endoncuclease?

1. Haemophilus influenzae
2. Escherichia coli
3. Agrobacterium tumefaciens
4. Bacillus amylase

Q. Which one of these is not a tool of recombinant DNA technology?

1. Restriction enzyme
2. Vector
3. Polymerase enzyme
4. Introns

Q. Explain the roles of the following with the help of an example each in recombinant DNA technology:
(a) Restriction Enzymes
(b) Plasmids.

Q. The restriction enzyme(s) used in recombinant DNA technology making staggered cuts in DNA leaving sticky ends is/are

1. Eco RI
2. Hind III
3. Bam HI
4. All of these

Q. The restriction enzyme(s) used in recombinant DNA technology making staggered cuts in DNA leaving sticky ends is/are

1. Eco RI
2. Hind III
3. Bam HI
4. All of these

Q. Some of the steps followed for molecular diagnosis of a pathogen are given. Identify their correct sequence from the options given below.
I. Electrophoresis of DNA fragments
II. Hybridisation with DNA probe
III. Digestion of DNA by restriction endonucleases
IV. Autoradiography
V. Transferring of DNA fragments on nitrocellulose membrane

1. III – I – II – V – IV
2. III – I – V – II – IV
3. I – V – III – II – IV
4. I – III – V – IV – II

Q. Which of the following enzymes are known as molecular scissors or molecular scalpels ?

1. DNA polymerases
2. Hydrolases
3. Ligases
4. Restriction endonucleases

Q. The restriction enzymes used in recombinant DNA technology that make staggered cuts in DNAleaving sticky ends is/are

1. Eco RI
2. Hind III
3. Bam HI
4. All of these

Q. Genetic engineering is possible because :

1. We can see DNA by electron, microscope
2. The phenomenon of transduction in bacteria is well understood
3. We can cut DNA at specific sites by restriction endonucleases
4. Restriction endonucleases purified from virus can be used in bacteria

Q. Assertion :Restriction enzymes of different organisms that recognize the identical sequences are called isoschizomers. Reason: They are present only in eukaryotes.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
3. Assertion is correct but Reason is incorrect.
4. Assertion is incorrect but Reason is correct.

Q. In transgenics, expression of transgene in target tissue is determined by ____________.

1. Reporter
2. Enhancer
3. Transgene
4. Promotor