Question

The term ‘molecular scissors’ refers to:
A. Recombinant DNA
B. Restriction enzyme
C. Taq polymerase
D. Palindromic sequence

Answer 1

The DNA performs various functions such as regulation of cell functions, cell division, coding for various proteins etc. it contains various sites which code for the working of cells. Thus, DNA requires various cell materials that help DNA to complete its function.

Complete answer:
There are various tools which are used in molecular biology and are responsible for various cell functions, out of which one is restriction enzymes. Restriction enzymes are also called molecular scissors. These are called restriction enzymes because these are used to cut the DNA strands at the specific sequences which are near recognition sites. The restriction enzymes are of two types, endonucleases and exonucleases. The endonucleases cut the DNA chains from the center of the chain. The exonucleases are used to cut the ends of the DNA chains.
Both the restriction enzymes cut the DNA by recognizing a particular sequence of the nucleotides which are called as the palindromic sequences. These sequences are found in every DNA and have their own restriction enzymes which are specific for them only. The palindromic sequences are necessary because they act as a restriction site for the cutting of DNA. These are usually present before the promoter region.
The recombinant DNA is the DNA which is formed by genetic recombination of a gene of interest from an organism and DNA from another organism which is not found naturally. The DNA is isolated from the organism and the gene of interest is separated from that DNA with the help of restriction enzymes. Further, the isolated gene of interest is attached to the DNA of other organisms with help of enzyme ligases.
The Taq polymerase is a thermostable DNA polymerase which is used in the amplification of DNA molecules in the process of Polymerase Chain Reaction (PCR). This DNA polymerase can withstand high temperature without getting denatured. This enzyme is obtained from an organism named Thermus aquaticus that is why it is called as Taq polymerase.

So, the correct answer is B.

Note: All the components of molecular biology are interconnected to each other. The Restriction enzymes are used to cut the DNA at the specific positions or sequences. These specific positions are labeled by the palindromic sequences which are recognized by the restriction enzymes. The isolated DNA is amplified by the help of Taq polymerase in PCR for observation of nucleotide behavior. The pieces of DNA are used in the recombinant DNA technology for the creation of genetically modified organisms.