Zoology MCQs for NEET — Practice Questions with Answers

Electroporation is a technique in which host cells are exposed to a pulse of high voltage current. This creates temporary pores in the cell membrane, allowing foreign DNA to enter the cell.

Transgenic organisms are those that have been genetically modified to contain and express foreign genes. Genetic engineering involves the direct manipulation of an organism's genes, often through the introduction of transgenic elements.

A cosmid is a type of hybrid plasmid that contains a cos site from the lambda phage. It does not contain genes coding for viral proteins, but it can replicate like plasmids, have antibiotic resistance markers, and has cos sites that help form circular DNA.

The correct materials used for coating microparticles in gene guns for transformation are gold or tungsten. These metals are chosen because they are dense enough to penetrate plant cells without causing excessive damage. Gold is especially preferred due to its inert nature, which minimizes any reactive interference with the DNA.

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.