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NEET Questions / Botany / Biotechnology and Its Applications
RNA interference (RNAi) technology is being explored for developing pest-resistant plants. Which statement about RNAi is INCORRECT?
The RNAi effect can be highly specific to the target pest.
The introduced dsRNA is processed into smaller interfering RNAs (siRNAs).
RNAi primarily works by blocking translation of target mRNA.
The RNAi trait is easily inherited through traditional plant breeding methods.
A new herbicide-tolerant crop variety has been developed. Which evaluation is MOST crucial before its commercial release, considering potential environmental impact?
Analysis of the nutritional content of the modified crop
Evaluation of the crop's yield compared to traditional varieties
Assessment of gene flow to wild relatives and the development of herbicide resistance in weeds
Study of the effects of the herbicide on non-target insects
A scientist aims to modify the human insulin gene to increase its binding affinity to the insulin receptor. Which amino acid substitution within the insulin A-chain is MOST likely to achieve this, considering its role in receptor interaction?
A. Valine at A3 to Leucine
B. Glycine at A1 to Glutamic acid
C. Isoleucine at A2 to Valine
D. Glutamine at A5 to Asparagine
During the production of genetically engineered human insulin, which of the following is NOT a critical step in ensuring the correct formation of disulfide bonds essential for the protein's biological activity?
Correct protein folding
Oxidation of cysteine residues
Cleavage of the proinsulin molecule
Glycosylation of the protein
Which specific enzymatic cleavage is crucial for converting proinsulin to active insulin in the production of genetically engineered human insulin?
A. Cleavage at the N-terminus of the A-chain
B. Cleavage at the C-terminus of the B-chain
C. Removal of the C-peptide by specific endopeptidases
D. Cleavage of disulfide bonds linking A and B chains
In the context of producing genetically engineered human insulin, why is the formation of inclusion bodies in E. coli sometimes considered advantageous despite requiring additional processing steps?
A. Inclusion bodies protect insulin from proteolytic degradation within the bacterial cell
B. Inclusion bodies directly facilitate the formation of correct disulfide bonds
C. Inclusion bodies enhance the solubility and secretion of insulin from the bacterial cell
D. Inclusion bodies simplify the purification process by eliminating the need for chromatography
A researcher is attempting to express human proinsulin in a eukaryotic expression system like yeast. Compared to bacterial systems, what distinct advantage does this offer concerning post-translational modifications?
A. Yeast can directly cleave proinsulin into active insulin without the need for enzymatic treatment
B. Yeast can perform glycosylation, which may enhance insulin stability or activity
C. Yeast prevents the formation of inclusion bodies, simplifying purification
D. Yeast systems eliminate the risk of endotoxin contamination
What is a primary concern regarding the immunogenicity of genetically engineered insulin produced in bacterial systems, and how is this typically addressed?
A. The altered amino acid sequence of engineered insulin is highly immunogenic; humanized antibodies are co-administered.
B. The use of antibiotic resistance genes in production vectors triggers immune reactions; marker-free vectors are used.
C. The lack of glycosylation in bacterially produced insulin increases its immunogenicity; glycosylation enzymes are added in vitro.
D. Bacterial contaminants like endotoxins can elicit immune responses; purification methods are employed to remove them.
A transgenic mouse expressing a human growth hormone gene exhibits gigantism. Researchers discover a second transgenic mouse line with the same human growth hormone gene construct, yet these mice show normal growth. Which of the following is the MOST LIKELY explanation for this discrepancy?
The second mouse line has a mutation in the mouse growth hormone receptor gene.
The human growth hormone gene is not being transcribed in the second mouse line.
Position effect variegation due to the transgene's insertion site in the second mouse line.
The second mouse line expresses an endogenous inhibitor of human growth hormone.
Which technique is NOT typically used for the production of transgenic animals?
Microinjection of DNA into the pronucleus of a fertilized egg
Retroviral infection of embryonic stem cells
Electroporation of fertilized eggs with recombinant DNA
Transfer of genetically modified embryonic stem cells into a blastocyst