Explanation: Due to the negative charge of the tRNA backbone, it is unlikely for the molecule to have a hydrophobic nature. Thus, hydrophobic interactions do not play any role in the structural stability of the molecule. On the other hand, the other interactions such as the hydrogen bonding lead to base pairing which leads to its classic clover leaf model.

Explanation: A histone variant CENP – A, is associated with the nucleosome that include centromeric DNA. In this region CENP – A replaces H3 subunit in the nucleosomes. These nucleosomes are incorporated into the kinetochore which mediates attachment of the chromosome to the mitotic spindle. The extended tail of CENP – A may generate these novel binding sites for other binding protein components of the kinetochore.

Explanation: Nucleosome sliding is a type of Nucleosome remodeling. It is facilitated by Nucleosome remodeling complex. It cannot be promoted alone by modifying histone tail unless a nucleosome remodeling complex comes along.

Explanation: As the genome size increases the DNA between two consecutive sequences increase, known as the Intergenic sequences. Thus, with the increase in genome complexity, regulatory sequences are required for the proper functioning of the different mechanisms. These regulatory sequences are stored in these Intergenic sequences.

Explanation: The complementary sequence of ATTGCAAT is TAACGTTA. Thus, when the first is read from left to right and the later read from right to left the sequence of the bases is exactly the same. This is the criteria for a sequence to be palindromic.

Explanation: Sodium dodecyl sulphate is a detergent, often used in biochemical preparations, binds to proteins and causes them to form a rod like structure. Most proteins bind SDS in the same ratio (1.4g per g of protein). Thus, the electrophoresis of proteins in an SDS – containing polyacrylamide gel separates them in order of their molecular masses. It is not known to have a similar effect on nucleic acids.

Explanation: The only organisms that are found to have positively supercoiled DNA are certain thermophiles, microorganisms living under conditions of extremely high temperature. Example of one such bacteria found in hot springs are Thermus aquaticus.

Explanation: Between the steps of DNA cleavage and DNA rejoining, the topoisomerase promotes the passage of a second segment of DNA through the break. Topoisomerase function thus involves DNA cleavage, strand passage and DNA rejoining in highly coordinated manner.

Explanation: DNA cloning typically involves a vector that carried the DNA insert into a host cell. Molecular cutters are important to incorporate the DNA insert into the vector thus giving rise to the chimera molecule. Hence cloning is complete if the organism replicates and the DNA insert replicates along with it.

Explanation: DNA sequencing is the process of determining the precise order of nucleotides within a DNA molecule. It includes the methods and technologies of restriction endonuclease, electrophoretic techniques and Polymerase Chain Reaction.

Explanation: Though unusual, pre – tRNA and pre – rRNAs also undergo splicing. In contrast to other splicing reactions, which involve the activity of catalytic RNAs, tRNA splicing is mediated by conventional protein enzymes. An endonuclease cleaves the pre – tRNA at the splice site to excise the intron, followed by the joining of the exons to form a mature tRNA molecule.