Define the terms 'codon' and 'anticodon"

A codon can be characterised as a sequence of three nucleotides or triplets present on mRNA, that encodes for a specific amino acid at the time of translation. Anticodon can be best defined as a three nucleotides sequence present on tRNA, which binds to the complementary sequence present on mRNA. Anticodon sequence determines the amino acid carried by the tRNA molecule.

Enlist the histones which form an octamer of nucleosome.

The nucleosome is found in the nucleus of the eukaryotic cell. It is the basic unit of DNA packaging into chromosomes. Histones are basic in nature which helps in the packaging process of DNA. Two units of H2A, H2B, H3, and H4 histone protein form an octamer of nucleosome. That appears as a bead on a string.

With the help of a suitable example illustrate ‘Palindrome’.

A palindrome refers to a word, phrase, or sentence that reads the same backwards and forward. Palindromic sequences are nucleic acid sequences on a double-stranded DNA or RNA strand that are read the same no matter from the 5' end of the sequence itself or from the 5' end of its complementary strand. These sequences have the potential to form hairpin structures. For example, given sequences of two strands are read the same from both directions 5' to 3' or 3' to 5': 5'-----GAATTC-----3' 3'-----CTTAAG-----5'