Principles of Genetics — DU B. Sc. (Hons) Biomedical Previous Year Question Papers

. (if Determine the linear örder of the genes on the chromosome (ii) Calculate the recombinant distances between the three loci. (DSC) (NEP) (b) Attempt five questions in all. (d) Subparts of the questions should be attempted 1. (a) Mention the contribution of any four scientists given below: ..." 4x1=4 (i). Rosalind Franklin (i1) Alfred Sturtevant (iii) Joe Fin Tjio and Albert Levan (iv) Bateson and Punnet Hermann Muller (b) State whether the following statements are thue. or false and Justify (Any foux) : 4x2=8 (i) Genetic variation arisestonly due to it* mutations in DNA sequence. in Drosophila salivary glands (v). Crossing" over always results in recombination between genes. (c) Answer the following in one word (Any four): 4x1=4 (i.. or nomato that allows accurate copying.. (ii) Interaction where, one gene mask anothers (iti) DNA packaging unit consisting of histones and DNA (iv) Genetic system where sex depends on X:A w. ratio. in Drosophila melanogaster. (v) Mutation with no change in amino acid sequence (a) DNA called the blueprint of life. Explain brietly. 2. Differentiate between the following (Any four) : "r: 4:5×4=18 (iii) Autosomal and Sex-linked inheritance (iv) Sex limited and sex influenced traits. (v) Constitutive and facultative heterochromatin 3. Write a short note on the following (Any four) : (i) Frameshift mutations* (ii) G-banding and Q-banding Maternal effect in stail shell coiling (iv) Mendel's laws of inheritance (v) Loss-of-function and Gain-of-function mutations 4. (a) Differentiate between insertion elements and transposons. Brietly describe different types of " "möbile genetic elements found in different organisms with examples öf each. (b)" What do yoü understand by maternal effect. Does it follow Mendels laws of inheritance. Explain ‹0 with a suitable example!** Explain Lyons hypothesis with the aid of ar example. 6 5. (a) Explain cytoplasmic inheritance with aid of suitable examples. (b) Explain the interallelic gene interactions that deviate from Mendels dihybrid ratio with aid of one example each. 6. (a) In D. melanogaster, cherub wings (ch), black body (b), and cinnabar eyes (cn) result from recessive alleles that are all located on chromosome 2. A homozygous wild-type fly was! mated with a cherub, black and cinnabar fly, and the resulting Fi females were test-crossed with cherub, black and cinnabar males. The following progenies were produced from the testcross: