Cell Growth and Regulation — DU B.Sc. (Hons.) Zoology Previous Year Question Papers

2. Explain how chromatin structure and nucleosome positioning influence transcription. 4. Importance of checkpoints in cell cycle. What happened if G2 checkpoints fail and cell enters mitosis. 15 6. (a) Explain how radiation and chemical carcinogens induce cancer at the molecular level. 7 (b) How was the first human oncogene (ras) identified using gene transfer experiments? 7. Write short notes on any three of the following: 3×5=15 (i) Protein Noggin influence neurogenesis (ii) Loss of E-cadherin and carcinomas. (iii) Four transcription factors used to create iPSCs (iv) Nucleosome positioning (c) Draw labeled diagrams wherever necessary. 1. (a) Define the following (Any Six): (i) Silencers (iii) Growth factors (iv) Cell lines (b) Differentiate between the following (Any (ii) Reproductive Cloning vs. Therapeutic (iii) Restriction Point and DNA Damage (iv) Activators and repressors. (v) Oncogenes and tumour suppressor genes (c) Write the significance of the following (Any (ii) CREB transcription factor (iii) Chromatin remodeling complexes (v) Casein Kinase-1 (CK1) (d) Briefly explain with example/use/role the following (Any Four): 1x4=4 (i) Adult stem cell. (ii) Gene enhancers. (v) Regenerative medicine (e) Fill in the blanks (Any Four): 1x4=4 (i) The proteins that regulate cell cycle progression by activating CDKs are called... (ii) Epidermal Growth Factor (EGF) stimulates .... of cells. (iii) DNA sequences that enhance transcription from a distance are called (iv) The ......... gene is the most common target of genetic alterations in human malignancies. (v) The pathway that commonly leads to activation of transcription factor CREB is the .... pathway. (f) Expand the following (Any Four) 1x4=4 (ill) MAPK