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As specific activity increases, purity also increases.

To utilize barnase/ barstar system 

Sparging / forced aeration

No, animal cells need a CO₂ incubator

Due to the existence of overlapping genes, splice variants, post translational and post transcriptional modifications.

A mini version of the commercial plant is essential to validatelab processes on an intermediate scale before attempting commercial production.

u = 2.303(log X_t – log X₀)/t

u = 2.303(log 10⁷ - log 10⁴)/4

(X₀ = 10⁴ , X_t = 10⁷ , t = 4 hours)

Solving the above equation by using the values,

we get,

u = 1.73/hr

t_d = 0.693/1.73

= 0.4 hrs

0.4 x 60 = 24 mins

Serum is a source of various amino acids, hormones, lipids, vitamins,polyamines and salts containing various ions. Serum also contains growth factors required for proliferation and attachment of animal cells to culture vessels. 

Antibiotics control the growth of bacterial and fungal contaminants

Ti plasmid vectors are disarmed because they do not require any chemical or equipments to transfer the gene of interest into plant cells. 

The gene of interest is incorporated in the T- DNA region of Ti plasmid

The convention for naming restriction enzymes is that the first letter to the name comes from the Genus and the second two letters come from species and third letter indicates the strain of the prokaryotic cell from which they are isolated e.g., EcoRI comes from Escherichia coli RI, here R stands for the strain and I follows the order in which the enzyme was isolated.

(i) - Identifying the restriction endonuclease that recognises the palindromic nucleotide sequence of the desired gene. 

- The restriction endonuclease inspects the DNA sequences 

- finds and recognises the site 

- Cuts each of the double helix at the specific point 

- A little away from the centre of the palindromic site 

- between the same two bases on the opposite strand. 

- Makes the over hanging stretch single stranded portion as a sticky end. 

(ii) - By PCR/Polymelase Chain Reaction 

- Desired gene is synthesised in vitro 

- DNA is denatured 

- Annealed using two sets of primers 

- Thermostable Taq polymerase extends the primers using nucleotides (provided in the reaction and genomic DNA as template) 

- Amplified fragments are ligated.

EcoRI first inspects the length of a DNA sequence, then it binds with specific recognition sequence of DNA, EcoRI cut each of the two strands of double helix at specific points in their sugar-phosphate backbones//diagram with same value points to be accepted.

‘Cry’ gene codes for Bt toxin.

Correct answer is (c) liposome + inactivated HIV

Virosomes are used in gene delivery.

The clinical trials of somatic cell gene therapy have been employed for the treatment of disorders like cancer, rheumatoid arthritis, SCID, Gaucher’s disease, familial hypercholesterolemia, haemophilia, phenylketonuria, cystic fibrosis, sickle-cell anaemia, Duchenne muscular dystrophy, emphysema, thalassemia, etc.

In the process of r-DNA technology, if two separate restriction enzymes are used to cut vector and donor DNA, then it will result in fragments with different sticky ends which will not be complementary to each other.

Biological tools used for transformation of recombinant DNA are enzymes, cloning vectors (vehicle DNA) and competent host (cloning organisms).

Various enzymes used in recombinant DNA technology are lysozymes, nucleases (exonucleases, endonucleases, restriction endonucleases), DNA ligases, DNA polymerases, alkaline phosphatases, reverse transcriptases, etc.

1. Different restriction enzymes commonly used in r-DNA technology are Alu I, Bam HI, Eco RI, Hind II, Hind III, Pst I, Sal I, Taq I, Mbo II, Hpa I, Bgl I, Not I, Kpn I, etc.

2. They are the molecular scissors which recognize and cut the phosphodiester back bone of DNA on both strands, at highly specific sequences. 

3. The sites recognized by them are called recognition sequences or recognition sites. 

4. Different restriction enzymes found in different organisms recognize different nucleotide sequences and therefore cut DNA at different sites. 

5. Restriction cutting may result in DNA fragments with blunt ends or cohesive or sticky ends or staggered ends (having short, single stranded projections). 

6. Restriction endonucleases like Bam HI and EcoRI produce fragments with sticky ends. 

7. Restriction endonucleases like Alu I, Hind III produce fragments with blunt ends

8. Type I restriction endonucleases fuction simultaneously as endonuclease and methylase e.g. EcoK. 

9. Type II restriction endonucleases have separate cleaving and methylation activities. They are more stable and are used in r-DNA technology e.g. EcoRI, Bgll. They cut DNA at specific sites within the palindrome. 

10. Type III restriction endonucleases cut DNA at specific non-palindromic sequences e.g. Hpal, MboII. 

11. In bacterial cells, REs destroy various viral DNAs that might enter the cell, thus restricting the potential growth of the virus.

The biological tools used in r-DNA technology are various enzymes, cloning vectors and competent hosts. 

(1) Enzymes:

• Enzymes like lysozymes, nucleases (exonucleases and endonucleases), DNA ligase, reverse transcriptase, DNA polymerase, alkaline phosphatases, etc. are used in r-DNA technology. 
• The restriction endonucleases are used as biological or molecular scissors. They are able to cut a DNA molecule at a specific recognition site

(2) Vectors:

• Vectors are DNA molecules which carry foreign DNA segment and replicate inside the host cell. 
• Vectors may be plasmids, bacteriophages (M13, lambda virus), cosmid, phagemids, BAC (bacterial artificial chromosome), YAC (yeast artificial chromosome), transposons, baculoviruses and mammalian artificial chromosomes (MACs). 
• Most commonly used vectors are plasmid vectors (pBR 322, pUC, Ti plasmid) and bacteriophages (lamda phage, M13 phage).

(3) Competent host cells:

1. They are bacteria like Bacillus haemophilus, Helicobacter pyroliand E. coli. 

2. Mostly E. coli is used for the transformation with recombinant DNA.