CBSE Class 12 Biology — Molecular Basis of Inheritance

(a) (i) Watson and Crick's discovery of double helical structure was based on which two findings. Also mention the name of the scientists associated with these findings. [2] (ii) Write down the salient features of double helix structure of DNA (any three points). [3] OR (b) Given below is a stretch of DNA showing the coding strand of structural gene of transcription unit. 5' - ATG ACC GTA TTT TCT GTA GTG CCC GTA CTT CAG GCA TTA 3' (i) Write the corresponding template strand and m-RNA strand that will be transcribed along with its polarity. [2] (ii) If GUA of transcribed mRNA is an intron, then depict the sequence involved in formation of mRNA / mature / processed hnRNA strand: (1) In a bacterium [1] (2) In humans [1] (iii) How many amino acids the resulting polypeptide will have after the process of translation in humans? [1]