NEET Practice Questions (MCQs) with Answers & Solutions

DNA ligase is the enzyme responsible for linking the antibiotic resistance gene with the plasmid vector. This enzyme facilitates the formation of phosphodiester bonds between the DNA fragments, thus joining them together. Exonucleases and endonucleases are enzymes that cut DNA, and DNA polymerase is involved in DNA synthesis, not in ligation.

Genetic engineering has been successfully used to produce transgenic mice for testing the safety of polio vaccines before their use in humans. These transgenic mice models help in studying the effects and safety of the vaccine, which is a critical step before human clinical trials.

Order of nucleotides in mRNA determines the amino acid sequence in the polypeptide chain of protein during translation. As genetic code is universal, hence same order of nucleotides will result in the incorporation of same amino acid during translation in various organisms. That is why production of human protein in bacteria by genetic engineering is possible.

So, the correct option is 'Genetic code is universal

Restriction endonucleases are enzymes that cut DNA molecules at specific sequences, known as recognition sites. This precise cutting is essential for genetic engineering and molecular cloning. For NEET students, remember that these enzymes act like molecular scissors, making specific cuts in the DNA.

In a transgenic organism, reporter genes are used to determine whether a particular DNA construct has been successfully introduced into a cell, organ or tissue. Whereas promoter is the region of DNA that initiates the DNA transcription, an enhancer is the sequence of DNA that enhances the transcription when binds to the specific proteic and transgene is the gene that taken from the genome of one organism and introduces into the genome of another organism.

A variable number tandem repeat (or VNTR) is a location in a genome where a short nucleotide sequence is organized as a tandem repeat. These can be found on many chromosomes, and often show variations in length (number of repeats) among individuals.

Bt in Bt cotton stands for Bacillus thuringiensis, a bacterium that produces toxins harmful to certain insects. Bt cotton is genetically modified to express this toxin, providing resistance against pests like the bollworm. NEET students should remember that Bacillus thuringiensis is the key to understanding the pest-resistant properties of Bt cotton.

The total number of nitrogenous bases in human genomes estimated were 3.1 billion.

The first hormone to be produced by genetic engineering was Insulin. This milestone was achieved in 1982 when recombinant DNA technology was used to produce human insulin in bacteria. The genetically engineered insulin, known as Humulin, is identical to human insulin and has been a breakthrough in diabetes treatment.