The process of introducing foreign DNA into a plant cell using Agrobacterium tumefaciens is known as:
Answer: B
Agrobacterium tumefaciens naturally transfers T-DNA into plant cells, making it an efficient vector for plant genetic engineering. This process is called agro-transformation.
Q.2Medium
In CRISPR-Cas9 gene editing, what does the 'guide RNA' do?
Answer: B
The guide RNA is a synthetic RNA molecule that binds to the target DNA sequence and directs the Cas9 nuclease to cut at the correct location.
Q.3Medium
Which of the following statements about Golden Rice is correct?
Answer: B
Golden Rice is engineered to produce beta-carotene (pro-vitamin A), though its approval for cultivation in India was granted only in 2021. It aims to address Vitamin A deficiency.
Q.4Medium
What is the role of a 'selectable marker' gene in genetic engineering?
Answer: A
Selectable marker genes (like antibiotic resistance genes) allow researchers to identify and select cells that have successfully taken up the foreign DNA.
Q.5Medium
In the context of genetic engineering, what does 'homologous recombination' mean?
Answer: B
Homologous recombination involves the exchange of DNA segments between regions with similar sequences, allowing precise insertion of genes at specific locations.
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Q.6Medium
Which technique would be most suitable for introducing multiple genes simultaneously into a plant cell?
Answer: B
Gene stacking or pyramiding involves incorporating multiple transgenes into a single organism, useful for combining multiple desired traits like herbicide resistance and pest resistance.
Q.7Medium
What is the major concern regarding the long-term cultivation of Bt cotton in India?
Answer: B
Continuous exposure to Bt toxin has led to the development of resistance in target insect populations in some regions, necessitating resistance management strategies and refugium planting.
Q.8Medium
Consider a genetic engineer wants to produce insulin using genetically modified bacteria. Which of the following is the correct sequence of steps?
Answer: C
The correct sequence is: (1) Insert the insulin gene into a vector, (2) Introduce the vector into bacteria (transformation), (3) Grow the bacteria in culture, (4) Extract and purify the expressed insulin protein.
Q.9Medium
Which of the following regulatory bodies in India is responsible for the approval of GM crops?
Answer: B
The GEAC (Genetic Engineering Appraisal Committee) is the apex body in India that approves the environmental release and commercialization of GM crops after rigorous evaluation.
Q.10Medium
What is the primary advantage of using homologous recombination over random integration in genetic engineering?
Answer: B
Homologous recombination enables precise insertion of genes at specific genomic locations with high accuracy, reducing off-target effects. This is more predictable than random integration.
Q.11Medium
Bt Brinjal, developed in India, produces a toxin that is toxic to which major pest?
Answer: B
Bt Brinjal contains a gene from Bacillus thuringiensis that produces Cry1Ac toxin, which is specifically toxic to the Brinjal Fruit and Shoot Borer (BFSB), a major pest affecting brinjal cultivation in India.
Q.12Medium
Which Indian state first approved the cultivation of Bt Cotton commercially?
Answer: B
Bt Cotton was first commercialized in Gujarat in 2002 after receiving GEAC approval. It has since become one of the most widely cultivated GM crops in India.
Q.13Medium
In the process of DNA sequencing using Sanger's method, what does the term 'dideoxynucleotides' refer to?
Answer: B
Dideoxynucleotides (ddNTPs) lack the hydroxyl group (-OH) at the 3' carbon of the sugar, preventing further DNA chain elongation. This terminates DNA synthesis and is fundamental to Sanger sequencing.
Q.14Medium
What is the primary concern associated with the use of antibiotic resistance genes as selectable markers in genetic engineering?
Answer: B
Horizontal gene transfer of antibiotic resistance genes from GM organisms to pathogenic bacteria is a major ecological and health concern. This has led to development of alternative marker systems and increased scrutiny by regulatory bodies.
Q.15Medium
Which of the following techniques would be most appropriate for introducing multiple genes simultaneously into a plant genome?
Answer: B
Gene gun can deliver multiple genes at once through particle bombardment. While Agrobacterium can be used for multiple genes, it's typically better for single or limited gene transfers. Gene gun offers better efficiency for multi-gene introduction.
Q.16Medium
In CRISPR-Cas9 technology, what is the role of the single guide RNA (sgRNA)?
Answer: B
The sgRNA is a synthetic RNA molecule that guides the Cas9 endonuclease to the specific target DNA sequence through complementary base pairing, ensuring precise gene editing at the desired location.
Q.17Medium
Which of the following best describes 'off-target effects' in CRISPR-Cas9 gene editing?
Answer: B
Off-target effects occur when Cas9 cuts at genomic sites that are similar but not identical to the intended target sequence. This can cause undesired mutations and is a significant concern in therapeutic applications.
Q.18Medium
What is the significance of the PAM sequence in CRISPR-Cas9 gene editing?
Answer: B
The Protospacer Adjacent Motif (PAM) is a 2-6 nucleotide sequence immediately next to the target site that is essential for Cas9 to recognize and cleave the DNA.
Q.19Medium
Which technique allows for the production of multiple identical copies of a DNA segment in vitro?
Answer: B
PCR amplifies specific DNA segments exponentially in cycles of heating and cooling, creating millions of copies without requiring bacterial cells or cloning vectors.
Q.20Medium
In Agrobacterium tumefaciens-mediated transformation, which part of the bacterium integrates into plant DNA?
Answer: B
Agrobacterium tumefaciens naturally transfers the T-DNA region from its Ti (Tumor-inducing) plasmid into plant cell chromosomes, making it an excellent biological vector for plant genetic engineering.
