NEET Zoology - MCQ Practice Questions

Restriction endonucleases recognize and cut DNA at specific palindromic sequences, producing sticky or blunt ends used in cloning.

Plasmids are small, circular DNA molecules used as vectors to carry and transfer foreign genes into host cells during genetic engineering.

Bt cotton contains foreign genes from Bacillus thuringiensis, making it a true transgenic organism. Others are produced by conventional breeding or mutation.

PCR (Polymerase Chain Reaction) is a molecular technique for amplifying specific DNA sequences through repeated cycles of denaturation, annealing, and extension.

DNA ligase catalyzes the formation of phosphodiester bonds between adjacent nucleotides, joining DNA fragments together during cloning.

Golden Rice is genetically modified to produce beta-carotene (provitamin A), addressing vitamin A deficiency in developing countries.

Southern blotting uses labeled probes to identify specific DNA sequences in clones, allowing isolation of desired clones from genomic libraries.

CRISPR-Cas9 is faster, cheaper, and more precise than traditional gene editing methods like zinc finger nucleases or TALENs.

Bt Cotton is the most extensively cultivated GM crop in India since its introduction in 2002, covering millions of hectares across multiple states.

Selectable marker genes (like antibiotic resistance genes) allow researchers to identify and select only those cells that have successfully incorporated the recombinant plasmid.

Recombinant human insulin produced through genetic engineering is a major medical biotechnology application, revolutionizing diabetes treatment.

DNA fingerprinting uses variable DNA regions to create unique profiles for identification in forensics, paternity testing, and population studies.

Ex vivo gene therapy involves isolating cells from the patient, modifying them genetically outside the body, and then reintroducing them, reducing immune reactions.

RNAi uses small interfering RNAs (siRNA) or short hairpin RNA (shRNA) to target and degrade specific mRNA molecules, leading to gene silencing.

Chimeric genes combine regulatory sequences from one organism with coding sequences from another, creating novel genetic constructs for transgenic organism development.

CSIR-Institute of Genomics and Integrative Biology (IGIB) has been at the forefront of developing CRISPR-based diagnostic tools for various diseases in India.

Agrobacterium tumefaciens naturally transfers its T-DNA into plant cells, making it an excellent natural vector for creating transgenic plants.

Reverse transcriptase, derived from retroviruses, synthesizes complementary DNA (cDNA) from an mRNA template, essential for expressing eukaryotic genes in prokaryotes.

Major concerns include the development of resistance in target insects, impacts on non-target beneficial organisms, and long-term ecological effects of Bt crop cultivation.

Microinjection is the standard technique for creating transgenic animals by directly injecting DNA into the pronucleus of a fertilized egg, allowing integration into the genome.